Sensim Math · Depth 한국어

← 2-2 · Convert to one unit, then compare lengths · Length as Sum of Parts with Unit Matching

Convert to one unit, then compare lengths · 12 practice problems

2.MD.A.14.MD.A.1

Generated variants — 12

Freshly produced from the archetype’s parameters — problem, figure, and solution derived together.

Variant 1 answer: From shortest to tallest: fire station (199 in), post office (20 ft 5 in), school (280 in).

The post office is 20 ft 5 in20\ \text{ft}\ 5\ \text{in} tall, the school is 280 in280\ \text{in} tall, and the fire station is 199 in199\ \text{in} tall. List the buildings in order from shortest to tallest.

Show solution

Understand

Three buildings have heights given in mixed units: the post office is 20 ft 5 in, the school is 280 in, and the fire station is 199 in. Put the buildings in order from shortest to tallest.

Givens
  • Post office height: 20 ft 5 in.
  • School height: 280 in.
  • Fire station height: 199 in.
  • 1 foot = 12 inches.
Unknowns
  • The ordering of the three buildings from shortest to tallest.
Constraints
  • Heights must be compared in a single common unit (inches).

Plan

#8 Analyze the Units · also uses: #2 Make a Systematic List

The heights are in different units (feet-and-inches versus inches), so they can't be compared directly. First convert everything to one unit (inches), then list the three numbers and order them.

Execute

#8 Analyze the Units 4.MD.A.1
Change 20 ft 5 in into inches. Each foot is 12 inches, so 20 feet is 20 times 12, then add the extra 5 inch.
20×12=240,240+5=24520 \times 12 = 240,\quad 240 + 5 = 245
Knowing 1 ft = 12 in lets us turn a larger unit into the smaller unit so all three heights share one unit.
#2 Make a Systematic List 2.MD.A.1
Now every height is in inches: post office 245 in, school 280 in, fire station 199 in.
245, 280, 199245,\ 280,\ 199
Writing them in one common unit makes a straight number comparison possible.
#2 Make a Systematic List 2.MD.A.1
Compare the three inch values: 199 is least, then 245, then 280 is greatest. So fire station is shortest, post office is next, school is tallest.
199<245<280199 < 245 < 280
Once numbers share a unit, ordering them is just comparing whole numbers.
Answer: From shortest to tallest: fire station (199 in), post office (20 ft 5 in), school (280 in).

Review

All three are a few hundred inches (around 20-30 feet), reasonable building heights, and the order 199 < 245 < 280 inches is correct. Converting back, 245 in = 20 ft 5 in matches the post office.

Convert everything to feet-and-inches instead and compare the feet first, then the leftover inches; the order comes out the same.

Standards · min grade 4

  • 4.MD.A.1 Know relative sizes of measurement units and convert larger to smaller units — Converting 20 ft 5 in into inches using 1 ft = 12 in.
  • 2.MD.A.1 Measure the length of an object by selecting and using appropriate tools — Comparing and ordering the three heights once expressed in the same unit (inches).
💡 Make every height use the same unit first, then it's just Grade 2 'which number is bigger' comparing!
Variant 2 answer: From shortest to tallest: fire station (267 in), post office (24 ft 1 in), school (320 in).

The post office is 24 ft 1 in24\ \text{ft}\ 1\ \text{in} tall, the school is 320 in320\ \text{in} tall, and the fire station is 267 in267\ \text{in} tall. List the buildings in order from shortest to tallest.

Show solution

Understand

Three buildings have heights given in mixed units: the post office is 24 ft 1 in, the school is 320 in, and the fire station is 267 in. Put the buildings in order from shortest to tallest.

Givens
  • Post office height: 24 ft 1 in.
  • School height: 320 in.
  • Fire station height: 267 in.
  • 1 foot = 12 inches.
Unknowns
  • The ordering of the three buildings from shortest to tallest.
Constraints
  • Heights must be compared in a single common unit (inches).

Plan

#8 Analyze the Units · also uses: #2 Make a Systematic List

The heights are in different units (feet-and-inches versus inches), so they can't be compared directly. First convert everything to one unit (inches), then list the three numbers and order them.

Execute

#8 Analyze the Units 4.MD.A.1
Change 24 ft 1 in into inches. Each foot is 12 inches, so 24 feet is 24 times 12, then add the extra 1 inch.
24×12=288,288+1=28924 \times 12 = 288,\quad 288 + 1 = 289
Knowing 1 ft = 12 in lets us turn a larger unit into the smaller unit so all three heights share one unit.
#2 Make a Systematic List 2.MD.A.1
Now every height is in inches: post office 289 in, school 320 in, fire station 267 in.
289, 320, 267289,\ 320,\ 267
Writing them in one common unit makes a straight number comparison possible.
#2 Make a Systematic List 2.MD.A.1
Compare the three inch values: 267 is least, then 289, then 320 is greatest. So fire station is shortest, post office is next, school is tallest.
267<289<320267 < 289 < 320
Once numbers share a unit, ordering them is just comparing whole numbers.
Answer: From shortest to tallest: fire station (267 in), post office (24 ft 1 in), school (320 in).

Review

All three are a few hundred inches (around 20-30 feet), reasonable building heights, and the order 267 < 289 < 320 inches is correct. Converting back, 289 in = 24 ft 1 in matches the post office.

Convert everything to feet-and-inches instead and compare the feet first, then the leftover inches; the order comes out the same.

Standards · min grade 4

  • 4.MD.A.1 Know relative sizes of measurement units and convert larger to smaller units — Converting 24 ft 1 in into inches using 1 ft = 12 in.
  • 2.MD.A.1 Measure the length of an object by selecting and using appropriate tools — Comparing and ordering the three heights once expressed in the same unit (inches).
💡 Make every height use the same unit first, then it's just Grade 2 'which number is bigger' comparing!
Variant 3 answer: From shortest to tallest: fire station (290 in), post office (27 ft 8 in), school (350 in).

The post office is 27 ft 8 in27\ \text{ft}\ 8\ \text{in} tall, the school is 350 in350\ \text{in} tall, and the fire station is 290 in290\ \text{in} tall. List the buildings in order from shortest to tallest.

Show solution

Understand

Three buildings have heights given in mixed units: the post office is 27 ft 8 in, the school is 350 in, and the fire station is 290 in. Put the buildings in order from shortest to tallest.

Givens
  • Post office height: 27 ft 8 in.
  • School height: 350 in.
  • Fire station height: 290 in.
  • 1 foot = 12 inches.
Unknowns
  • The ordering of the three buildings from shortest to tallest.
Constraints
  • Heights must be compared in a single common unit (inches).

Plan

#8 Analyze the Units · also uses: #2 Make a Systematic List

The heights are in different units (feet-and-inches versus inches), so they can't be compared directly. First convert everything to one unit (inches), then list the three numbers and order them.

Execute

#8 Analyze the Units 4.MD.A.1
Change 27 ft 8 in into inches. Each foot is 12 inches, so 27 feet is 27 times 12, then add the extra 8 inch.
27×12=324,324+8=33227 \times 12 = 324,\quad 324 + 8 = 332
Knowing 1 ft = 12 in lets us turn a larger unit into the smaller unit so all three heights share one unit.
#2 Make a Systematic List 2.MD.A.1
Now every height is in inches: post office 332 in, school 350 in, fire station 290 in.
332, 350, 290332,\ 350,\ 290
Writing them in one common unit makes a straight number comparison possible.
#2 Make a Systematic List 2.MD.A.1
Compare the three inch values: 290 is least, then 332, then 350 is greatest. So fire station is shortest, post office is next, school is tallest.
290<332<350290 < 332 < 350
Once numbers share a unit, ordering them is just comparing whole numbers.
Answer: From shortest to tallest: fire station (290 in), post office (27 ft 8 in), school (350 in).

Review

All three are a few hundred inches (around 20-30 feet), reasonable building heights, and the order 290 < 332 < 350 inches is correct. Converting back, 332 in = 27 ft 8 in matches the post office.

Convert everything to feet-and-inches instead and compare the feet first, then the leftover inches; the order comes out the same.

Standards · min grade 4

  • 4.MD.A.1 Know relative sizes of measurement units and convert larger to smaller units — Converting 27 ft 8 in into inches using 1 ft = 12 in.
  • 2.MD.A.1 Measure the length of an object by selecting and using appropriate tools — Comparing and ordering the three heights once expressed in the same unit (inches).
💡 Make every height use the same unit first, then it's just Grade 2 'which number is bigger' comparing!
Variant 4 answer: From shortest to tallest: fire station (333 in), post office (30 ft 0 in), school (400 in).

The post office is 30 ft 0 in30\ \text{ft}\ 0\ \text{in} tall, the school is 400 in400\ \text{in} tall, and the fire station is 333 in333\ \text{in} tall. List the buildings in order from shortest to tallest.

Show solution

Understand

Three buildings have heights given in mixed units: the post office is 30 ft 0 in, the school is 400 in, and the fire station is 333 in. Put the buildings in order from shortest to tallest.

Givens
  • Post office height: 30 ft 0 in.
  • School height: 400 in.
  • Fire station height: 333 in.
  • 1 foot = 12 inches.
Unknowns
  • The ordering of the three buildings from shortest to tallest.
Constraints
  • Heights must be compared in a single common unit (inches).

Plan

#8 Analyze the Units · also uses: #2 Make a Systematic List

The heights are in different units (feet-and-inches versus inches), so they can't be compared directly. First convert everything to one unit (inches), then list the three numbers and order them.

Execute

#8 Analyze the Units 4.MD.A.1
Change 30 ft 0 in into inches. Each foot is 12 inches, so 30 feet is 30 times 12, then add the extra 0 inch.
30×12=360,360+0=36030 \times 12 = 360,\quad 360 + 0 = 360
Knowing 1 ft = 12 in lets us turn a larger unit into the smaller unit so all three heights share one unit.
#2 Make a Systematic List 2.MD.A.1
Now every height is in inches: post office 360 in, school 400 in, fire station 333 in.
360, 400, 333360,\ 400,\ 333
Writing them in one common unit makes a straight number comparison possible.
#2 Make a Systematic List 2.MD.A.1
Compare the three inch values: 333 is least, then 360, then 400 is greatest. So fire station is shortest, post office is next, school is tallest.
333<360<400333 < 360 < 400
Once numbers share a unit, ordering them is just comparing whole numbers.
Answer: From shortest to tallest: fire station (333 in), post office (30 ft 0 in), school (400 in).

Review

All three are a few hundred inches (around 20-30 feet), reasonable building heights, and the order 333 < 360 < 400 inches is correct. Converting back, 360 in = 30 ft 0 in matches the post office.

Convert everything to feet-and-inches instead and compare the feet first, then the leftover inches; the order comes out the same.

Standards · min grade 4

  • 4.MD.A.1 Know relative sizes of measurement units and convert larger to smaller units — Converting 30 ft 0 in into inches using 1 ft = 12 in.
  • 2.MD.A.1 Measure the length of an object by selecting and using appropriate tools — Comparing and ordering the three heights once expressed in the same unit (inches).
💡 Make every height use the same unit first, then it's just Grade 2 'which number is bigger' comparing!
Variant 5 answer: From shortest to tallest: fire station (250 in), post office (22 ft 7 in), school (300 in).

The post office is 22 ft 7 in22\ \text{ft}\ 7\ \text{in} tall, the school is 300 in300\ \text{in} tall, and the fire station is 250 in250\ \text{in} tall. List the buildings in order from shortest to tallest.

Show solution

Understand

Three buildings have heights given in mixed units: the post office is 22 ft 7 in, the school is 300 in, and the fire station is 250 in. Put the buildings in order from shortest to tallest.

Givens
  • Post office height: 22 ft 7 in.
  • School height: 300 in.
  • Fire station height: 250 in.
  • 1 foot = 12 inches.
Unknowns
  • The ordering of the three buildings from shortest to tallest.
Constraints
  • Heights must be compared in a single common unit (inches).

Plan

#8 Analyze the Units · also uses: #2 Make a Systematic List

The heights are in different units (feet-and-inches versus inches), so they can't be compared directly. First convert everything to one unit (inches), then list the three numbers and order them.

Execute

#8 Analyze the Units 4.MD.A.1
Change 22 ft 7 in into inches. Each foot is 12 inches, so 22 feet is 22 times 12, then add the extra 7 inch.
22×12=264,264+7=27122 \times 12 = 264,\quad 264 + 7 = 271
Knowing 1 ft = 12 in lets us turn a larger unit into the smaller unit so all three heights share one unit.
#2 Make a Systematic List 2.MD.A.1
Now every height is in inches: post office 271 in, school 300 in, fire station 250 in.
271, 300, 250271,\ 300,\ 250
Writing them in one common unit makes a straight number comparison possible.
#2 Make a Systematic List 2.MD.A.1
Compare the three inch values: 250 is least, then 271, then 300 is greatest. So fire station is shortest, post office is next, school is tallest.
250<271<300250 < 271 < 300
Once numbers share a unit, ordering them is just comparing whole numbers.
Answer: From shortest to tallest: fire station (250 in), post office (22 ft 7 in), school (300 in).

Review

All three are a few hundred inches (around 20-30 feet), reasonable building heights, and the order 250 < 271 < 300 inches is correct. Converting back, 271 in = 22 ft 7 in matches the post office.

Convert everything to feet-and-inches instead and compare the feet first, then the leftover inches; the order comes out the same.

Standards · min grade 4

  • 4.MD.A.1 Know relative sizes of measurement units and convert larger to smaller units — Converting 22 ft 7 in into inches using 1 ft = 12 in.
  • 2.MD.A.1 Measure the length of an object by selecting and using appropriate tools — Comparing and ordering the three heights once expressed in the same unit (inches).
💡 Make every height use the same unit first, then it's just Grade 2 'which number is bigger' comparing!
Variant 6 answer: From shortest to tallest: school (290 in), post office (26 ft 2 in), fire station (340 in).

The post office is 26 ft 2 in26\ \text{ft}\ 2\ \text{in} tall, the school is 290 in290\ \text{in} tall, and the fire station is 340 in340\ \text{in} tall. List the buildings in order from shortest to tallest.

Show solution

Understand

Three buildings have heights given in mixed units: the post office is 26 ft 2 in, the school is 290 in, and the fire station is 340 in. Put the buildings in order from shortest to tallest.

Givens
  • Post office height: 26 ft 2 in.
  • School height: 290 in.
  • Fire station height: 340 in.
  • 1 foot = 12 inches.
Unknowns
  • The ordering of the three buildings from shortest to tallest.
Constraints
  • Heights must be compared in a single common unit (inches).

Plan

#8 Analyze the Units · also uses: #2 Make a Systematic List

The heights are in different units (feet-and-inches versus inches), so they can't be compared directly. First convert everything to one unit (inches), then list the three numbers and order them.

Execute

#8 Analyze the Units 4.MD.A.1
Change 26 ft 2 in into inches. Each foot is 12 inches, so 26 feet is 26 times 12, then add the extra 2 inch.
26×12=312,312+2=31426 \times 12 = 312,\quad 312 + 2 = 314
Knowing 1 ft = 12 in lets us turn a larger unit into the smaller unit so all three heights share one unit.
#2 Make a Systematic List 2.MD.A.1
Now every height is in inches: post office 314 in, school 290 in, fire station 340 in.
314, 290, 340314,\ 290,\ 340
Writing them in one common unit makes a straight number comparison possible.
#2 Make a Systematic List 2.MD.A.1
Compare the three inch values: 290 is least, then 314, then 340 is greatest. So school is shortest, post office is next, fire station is tallest.
290<314<340290 < 314 < 340
Once numbers share a unit, ordering them is just comparing whole numbers.
Answer: From shortest to tallest: school (290 in), post office (26 ft 2 in), fire station (340 in).

Review

All three are a few hundred inches (around 20-30 feet), reasonable building heights, and the order 290 < 314 < 340 inches is correct. Converting back, 314 in = 26 ft 2 in matches the post office.

Convert everything to feet-and-inches instead and compare the feet first, then the leftover inches; the order comes out the same.

Standards · min grade 4

  • 4.MD.A.1 Know relative sizes of measurement units and convert larger to smaller units — Converting 26 ft 2 in into inches using 1 ft = 12 in.
  • 2.MD.A.1 Measure the length of an object by selecting and using appropriate tools — Comparing and ordering the three heights once expressed in the same unit (inches).
💡 Make every height use the same unit first, then it's just Grade 2 'which number is bigger' comparing!
Variant 7 answer: From shortest to tallest: school (180 in), post office (16 ft 5 in), fire station (220 in).

The post office is 16 ft 5 in16\ \text{ft}\ 5\ \text{in} tall, the school is 180 in180\ \text{in} tall, and the fire station is 220 in220\ \text{in} tall. List the buildings in order from shortest to tallest.

Show solution

Understand

Three buildings have heights given in mixed units: the post office is 16 ft 5 in, the school is 180 in, and the fire station is 220 in. Put the buildings in order from shortest to tallest.

Givens
  • Post office height: 16 ft 5 in.
  • School height: 180 in.
  • Fire station height: 220 in.
  • 1 foot = 12 inches.
Unknowns
  • The ordering of the three buildings from shortest to tallest.
Constraints
  • Heights must be compared in a single common unit (inches).

Plan

#8 Analyze the Units · also uses: #2 Make a Systematic List

The heights are in different units (feet-and-inches versus inches), so they can't be compared directly. First convert everything to one unit (inches), then list the three numbers and order them.

Execute

#8 Analyze the Units 4.MD.A.1
Change 16 ft 5 in into inches. Each foot is 12 inches, so 16 feet is 16 times 12, then add the extra 5 inch.
16×12=192,192+5=19716 \times 12 = 192,\quad 192 + 5 = 197
Knowing 1 ft = 12 in lets us turn a larger unit into the smaller unit so all three heights share one unit.
#2 Make a Systematic List 2.MD.A.1
Now every height is in inches: post office 197 in, school 180 in, fire station 220 in.
197, 180, 220197,\ 180,\ 220
Writing them in one common unit makes a straight number comparison possible.
#2 Make a Systematic List 2.MD.A.1
Compare the three inch values: 180 is least, then 197, then 220 is greatest. So school is shortest, post office is next, fire station is tallest.
180<197<220180 < 197 < 220
Once numbers share a unit, ordering them is just comparing whole numbers.
Answer: From shortest to tallest: school (180 in), post office (16 ft 5 in), fire station (220 in).

Review

All three are a few hundred inches (around 20-30 feet), reasonable building heights, and the order 180 < 197 < 220 inches is correct. Converting back, 197 in = 16 ft 5 in matches the post office.

Convert everything to feet-and-inches instead and compare the feet first, then the leftover inches; the order comes out the same.

Standards · min grade 4

  • 4.MD.A.1 Know relative sizes of measurement units and convert larger to smaller units — Converting 16 ft 5 in into inches using 1 ft = 12 in.
  • 2.MD.A.1 Measure the length of an object by selecting and using appropriate tools — Comparing and ordering the three heights once expressed in the same unit (inches).
💡 Make every height use the same unit first, then it's just Grade 2 'which number is bigger' comparing!
Variant 8 answer: From shortest to tallest: fire station (240 in), post office (23 ft 6 in), school (310 in).

The post office is 23 ft 6 in23\ \text{ft}\ 6\ \text{in} tall, the school is 310 in310\ \text{in} tall, and the fire station is 240 in240\ \text{in} tall. List the buildings in order from shortest to tallest.

Show solution

Understand

Three buildings have heights given in mixed units: the post office is 23 ft 6 in, the school is 310 in, and the fire station is 240 in. Put the buildings in order from shortest to tallest.

Givens
  • Post office height: 23 ft 6 in.
  • School height: 310 in.
  • Fire station height: 240 in.
  • 1 foot = 12 inches.
Unknowns
  • The ordering of the three buildings from shortest to tallest.
Constraints
  • Heights must be compared in a single common unit (inches).

Plan

#8 Analyze the Units · also uses: #2 Make a Systematic List

The heights are in different units (feet-and-inches versus inches), so they can't be compared directly. First convert everything to one unit (inches), then list the three numbers and order them.

Execute

#8 Analyze the Units 4.MD.A.1
Change 23 ft 6 in into inches. Each foot is 12 inches, so 23 feet is 23 times 12, then add the extra 6 inch.
23×12=276,276+6=28223 \times 12 = 276,\quad 276 + 6 = 282
Knowing 1 ft = 12 in lets us turn a larger unit into the smaller unit so all three heights share one unit.
#2 Make a Systematic List 2.MD.A.1
Now every height is in inches: post office 282 in, school 310 in, fire station 240 in.
282, 310, 240282,\ 310,\ 240
Writing them in one common unit makes a straight number comparison possible.
#2 Make a Systematic List 2.MD.A.1
Compare the three inch values: 240 is least, then 282, then 310 is greatest. So fire station is shortest, post office is next, school is tallest.
240<282<310240 < 282 < 310
Once numbers share a unit, ordering them is just comparing whole numbers.
Answer: From shortest to tallest: fire station (240 in), post office (23 ft 6 in), school (310 in).

Review

All three are a few hundred inches (around 20-30 feet), reasonable building heights, and the order 240 < 282 < 310 inches is correct. Converting back, 282 in = 23 ft 6 in matches the post office.

Convert everything to feet-and-inches instead and compare the feet first, then the leftover inches; the order comes out the same.

Standards · min grade 4

  • 4.MD.A.1 Know relative sizes of measurement units and convert larger to smaller units — Converting 23 ft 6 in into inches using 1 ft = 12 in.
  • 2.MD.A.1 Measure the length of an object by selecting and using appropriate tools — Comparing and ordering the three heights once expressed in the same unit (inches).
💡 Make every height use the same unit first, then it's just Grade 2 'which number is bigger' comparing!
Variant 9 answer: From shortest to tallest: post office (21 ft 9 in), school (275 in), fire station (310 in).

The post office is 21 ft 9 in21\ \text{ft}\ 9\ \text{in} tall, the school is 275 in275\ \text{in} tall, and the fire station is 310 in310\ \text{in} tall. List the buildings in order from shortest to tallest.

Show solution

Understand

Three buildings have heights given in mixed units: the post office is 21 ft 9 in, the school is 275 in, and the fire station is 310 in. Put the buildings in order from shortest to tallest.

Givens
  • Post office height: 21 ft 9 in.
  • School height: 275 in.
  • Fire station height: 310 in.
  • 1 foot = 12 inches.
Unknowns
  • The ordering of the three buildings from shortest to tallest.
Constraints
  • Heights must be compared in a single common unit (inches).

Plan

#8 Analyze the Units · also uses: #2 Make a Systematic List

The heights are in different units (feet-and-inches versus inches), so they can't be compared directly. First convert everything to one unit (inches), then list the three numbers and order them.

Execute

#8 Analyze the Units 4.MD.A.1
Change 21 ft 9 in into inches. Each foot is 12 inches, so 21 feet is 21 times 12, then add the extra 9 inch.
21×12=252,252+9=26121 \times 12 = 252,\quad 252 + 9 = 261
Knowing 1 ft = 12 in lets us turn a larger unit into the smaller unit so all three heights share one unit.
#2 Make a Systematic List 2.MD.A.1
Now every height is in inches: post office 261 in, school 275 in, fire station 310 in.
261, 275, 310261,\ 275,\ 310
Writing them in one common unit makes a straight number comparison possible.
#2 Make a Systematic List 2.MD.A.1
Compare the three inch values: 261 is least, then 275, then 310 is greatest. So post office is shortest, school is next, fire station is tallest.
261<275<310261 < 275 < 310
Once numbers share a unit, ordering them is just comparing whole numbers.
Answer: From shortest to tallest: post office (21 ft 9 in), school (275 in), fire station (310 in).

Review

All three are a few hundred inches (around 20-30 feet), reasonable building heights, and the order 261 < 275 < 310 inches is correct. Converting back, 261 in = 21 ft 9 in matches the post office.

Convert everything to feet-and-inches instead and compare the feet first, then the leftover inches; the order comes out the same.

Standards · min grade 4

  • 4.MD.A.1 Know relative sizes of measurement units and convert larger to smaller units — Converting 21 ft 9 in into inches using 1 ft = 12 in.
  • 2.MD.A.1 Measure the length of an object by selecting and using appropriate tools — Comparing and ordering the three heights once expressed in the same unit (inches).
💡 Make every height use the same unit first, then it's just Grade 2 'which number is bigger' comparing!
Variant 10 answer: From shortest to tallest: school (200 in), post office (25 ft 4 in), fire station (360 in).

The post office is 25 ft 4 in25\ \text{ft}\ 4\ \text{in} tall, the school is 200 in200\ \text{in} tall, and the fire station is 360 in360\ \text{in} tall. List the buildings in order from shortest to tallest.

Show solution

Understand

Three buildings have heights given in mixed units: the post office is 25 ft 4 in, the school is 200 in, and the fire station is 360 in. Put the buildings in order from shortest to tallest.

Givens
  • Post office height: 25 ft 4 in.
  • School height: 200 in.
  • Fire station height: 360 in.
  • 1 foot = 12 inches.
Unknowns
  • The ordering of the three buildings from shortest to tallest.
Constraints
  • Heights must be compared in a single common unit (inches).

Plan

#8 Analyze the Units · also uses: #2 Make a Systematic List

The heights are in different units (feet-and-inches versus inches), so they can't be compared directly. First convert everything to one unit (inches), then list the three numbers and order them.

Execute

#8 Analyze the Units 4.MD.A.1
Change 25 ft 4 in into inches. Each foot is 12 inches, so 25 feet is 25 times 12, then add the extra 4 inch.
25×12=300,300+4=30425 \times 12 = 300,\quad 300 + 4 = 304
Knowing 1 ft = 12 in lets us turn a larger unit into the smaller unit so all three heights share one unit.
#2 Make a Systematic List 2.MD.A.1
Now every height is in inches: post office 304 in, school 200 in, fire station 360 in.
304, 200, 360304,\ 200,\ 360
Writing them in one common unit makes a straight number comparison possible.
#2 Make a Systematic List 2.MD.A.1
Compare the three inch values: 200 is least, then 304, then 360 is greatest. So school is shortest, post office is next, fire station is tallest.
200<304<360200 < 304 < 360
Once numbers share a unit, ordering them is just comparing whole numbers.
Answer: From shortest to tallest: school (200 in), post office (25 ft 4 in), fire station (360 in).

Review

All three are a few hundred inches (around 20-30 feet), reasonable building heights, and the order 200 < 304 < 360 inches is correct. Converting back, 304 in = 25 ft 4 in matches the post office.

Convert everything to feet-and-inches instead and compare the feet first, then the leftover inches; the order comes out the same.

Standards · min grade 4

  • 4.MD.A.1 Know relative sizes of measurement units and convert larger to smaller units — Converting 25 ft 4 in into inches using 1 ft = 12 in.
  • 2.MD.A.1 Measure the length of an object by selecting and using appropriate tools — Comparing and ordering the three heights once expressed in the same unit (inches).
💡 Make every height use the same unit first, then it's just Grade 2 'which number is bigger' comparing!
Variant 11 answer: From shortest to tallest: fire station (230 in), post office (19 ft 11 in), school (260 in).

The post office is 19 ft 11 in19\ \text{ft}\ 11\ \text{in} tall, the school is 260 in260\ \text{in} tall, and the fire station is 230 in230\ \text{in} tall. List the buildings in order from shortest to tallest.

Show solution

Understand

Three buildings have heights given in mixed units: the post office is 19 ft 11 in, the school is 260 in, and the fire station is 230 in. Put the buildings in order from shortest to tallest.

Givens
  • Post office height: 19 ft 11 in.
  • School height: 260 in.
  • Fire station height: 230 in.
  • 1 foot = 12 inches.
Unknowns
  • The ordering of the three buildings from shortest to tallest.
Constraints
  • Heights must be compared in a single common unit (inches).

Plan

#8 Analyze the Units · also uses: #2 Make a Systematic List

The heights are in different units (feet-and-inches versus inches), so they can't be compared directly. First convert everything to one unit (inches), then list the three numbers and order them.

Execute

#8 Analyze the Units 4.MD.A.1
Change 19 ft 11 in into inches. Each foot is 12 inches, so 19 feet is 19 times 12, then add the extra 11 inch.
19×12=228,228+11=23919 \times 12 = 228,\quad 228 + 11 = 239
Knowing 1 ft = 12 in lets us turn a larger unit into the smaller unit so all three heights share one unit.
#2 Make a Systematic List 2.MD.A.1
Now every height is in inches: post office 239 in, school 260 in, fire station 230 in.
239, 260, 230239,\ 260,\ 230
Writing them in one common unit makes a straight number comparison possible.
#2 Make a Systematic List 2.MD.A.1
Compare the three inch values: 230 is least, then 239, then 260 is greatest. So fire station is shortest, post office is next, school is tallest.
230<239<260230 < 239 < 260
Once numbers share a unit, ordering them is just comparing whole numbers.
Answer: From shortest to tallest: fire station (230 in), post office (19 ft 11 in), school (260 in).

Review

All three are a few hundred inches (around 20-30 feet), reasonable building heights, and the order 230 < 239 < 260 inches is correct. Converting back, 239 in = 19 ft 11 in matches the post office.

Convert everything to feet-and-inches instead and compare the feet first, then the leftover inches; the order comes out the same.

Standards · min grade 4

  • 4.MD.A.1 Know relative sizes of measurement units and convert larger to smaller units — Converting 19 ft 11 in into inches using 1 ft = 12 in.
  • 2.MD.A.1 Measure the length of an object by selecting and using appropriate tools — Comparing and ordering the three heights once expressed in the same unit (inches).
💡 Make every height use the same unit first, then it's just Grade 2 'which number is bigger' comparing!
Variant 12 answer: From shortest to tallest: fire station (190 in), post office (18 ft 3 in), school (250 in).

The post office is 18 ft 3 in18\ \text{ft}\ 3\ \text{in} tall, the school is 250 in250\ \text{in} tall, and the fire station is 190 in190\ \text{in} tall. List the buildings in order from shortest to tallest.

Show solution

Understand

Three buildings have heights given in mixed units: the post office is 18 ft 3 in, the school is 250 in, and the fire station is 190 in. Put the buildings in order from shortest to tallest.

Givens
  • Post office height: 18 ft 3 in.
  • School height: 250 in.
  • Fire station height: 190 in.
  • 1 foot = 12 inches.
Unknowns
  • The ordering of the three buildings from shortest to tallest.
Constraints
  • Heights must be compared in a single common unit (inches).

Plan

#8 Analyze the Units · also uses: #2 Make a Systematic List

The heights are in different units (feet-and-inches versus inches), so they can't be compared directly. First convert everything to one unit (inches), then list the three numbers and order them.

Execute

#8 Analyze the Units 4.MD.A.1
Change 18 ft 3 in into inches. Each foot is 12 inches, so 18 feet is 18 times 12, then add the extra 3 inch.
18×12=216,216+3=21918 \times 12 = 216,\quad 216 + 3 = 219
Knowing 1 ft = 12 in lets us turn a larger unit into the smaller unit so all three heights share one unit.
#2 Make a Systematic List 2.MD.A.1
Now every height is in inches: post office 219 in, school 250 in, fire station 190 in.
219, 250, 190219,\ 250,\ 190
Writing them in one common unit makes a straight number comparison possible.
#2 Make a Systematic List 2.MD.A.1
Compare the three inch values: 190 is least, then 219, then 250 is greatest. So fire station is shortest, post office is next, school is tallest.
190<219<250190 < 219 < 250
Once numbers share a unit, ordering them is just comparing whole numbers.
Answer: From shortest to tallest: fire station (190 in), post office (18 ft 3 in), school (250 in).

Review

All three are a few hundred inches (around 20-30 feet), reasonable building heights, and the order 190 < 219 < 250 inches is correct. Converting back, 219 in = 18 ft 3 in matches the post office.

Convert everything to feet-and-inches instead and compare the feet first, then the leftover inches; the order comes out the same.

Standards · min grade 4

  • 4.MD.A.1 Know relative sizes of measurement units and convert larger to smaller units — Converting 18 ft 3 in into inches using 1 ft = 12 in.
  • 2.MD.A.1 Measure the length of an object by selecting and using appropriate tools — Comparing and ordering the three heights once expressed in the same unit (inches).
💡 Make every height use the same unit first, then it's just Grade 2 'which number is bigger' comparing!