← Choose a scale that fits the largest value · Read and Scale a Data Graph

Choose a scale that fits the largest value · 10 practice problems

3.MD.B.3

Generated variants — 10

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

Variant 1 easy answer: 4 squares

Representative Problem

The table shows the favorite flowers of the students at Mia's school. If this table is drawn as a bar graph in which one vertical grid square represents 55 students, find the least number of vertical grid squares the scale must have.

Table "Favorite Flower":

Flower Rose Tulip Lily Daisy Total
Number of students (?) 1010 66 1414 5050
  • (Number of students who like roses) == [ ] (10+6+14)=- (10 + 6 + 14) = [ ] (students)
  • Since [ ] students like roses, the vertical scale must reach at least [ ] students.
  • If one vertical grid square represents 55 students, the vertical scale needs at least [ ] squares.
Show solution
1 · Understandwhat's really being asked

A table lists how many students like roses, tulips (10), lilies (6), and daisies (14), with a total of 50. First find the missing rose count, then decide how many vertical grid squares a bar graph needs if one square stands for 5 students.

Givens
  • Tulip = 10, Lily = 6, Daisy = 14 students
  • Total = 50 students
  • One vertical grid square represents 5 students
Unknowns
  • The number of students who like roses
  • The least number of vertical grid squares the scale must have
Constraints
  • The scale must reach at least the largest single value
  • Each grid square stands for exactly 5 students
2 · Planchoose the strategy

#7 Identify Subproblems · also uses: #8 Analyze the Units

This is a two-step task: first recover the missing value from the total (a subtraction subproblem), then convert the largest value into grid squares using the 'students per square' unit.

3 · Execute3 carry out the plan

1Find the rose count

#7 Identify Subproblems 3.MD.B.3
Subtract the three known categories from the total to get the number of students who like roses.
50(10+6+14)=5030=2050 - (10 + 6 + 14) = 50 - 30 = 20
A total is the sum of its parts, so the missing part is the total minus the known parts.

2Find the largest value

#7 Identify Subproblems 3.MD.B.3
Compare the four counts: 20 (rose), 10 (tulip), 6 (lily), 14 (daisy). The largest is 20, so the scale must reach at least 20 students.
max(20,10,6,14)=20\max(20, 10, 6, 14) = 20
The tallest bar sets how high the scale must go.

3Convert students to grid squares

#8 Analyze the Units 3.MD.B.3
Each grid square is worth 5 students, so divide the largest value by 5 to find how many squares are needed.
20÷5=420 \div 5 = 4
If one square holds 5 students, then 20 students fill 4 squares exactly.
Answer: 4 squares
4 · Reviewdoes it hold up?

4 squares at 5 students each reach 20 students, matching the largest value, and 20 is bigger than every other count, so 4 squares is the smallest scale that fits.

Another way: Guess and check (tool 6): 3 squares reach only 15 students, too short for 20; 4 squares reach 20, which works, confirming 4 is the least.

Standardsmin grade 3
  • 3.MD.B.3 Draw and interpret scaled picture graphs and bar graphs — Choosing a vertical scale that fits the largest data value and counting the needed grid squares
💡Takeaway. This only needs Grade 3 bar-graph sense: find the biggest value, then count squares worth 5 each!
Variant 2 easy answer: 4 squares

Representative Problem

The table shows the favorite flowers of the students at Mia's school. If this table is drawn as a bar graph in which one vertical grid square represents 55 students, find the least number of vertical grid squares the scale must have.

Table "Favorite Flower":

Flower Rose Tulip Lily Daisy Total
Number of students (?) 1111 77 1313 5151
  • (Number of students who like roses) == [ ] (11+7+13)=- (11 + 7 + 13) = [ ] (students)
  • Since [ ] students like roses, the vertical scale must reach at least [ ] students.
  • If one vertical grid square represents 55 students, the vertical scale needs at least [ ] squares.
Show solution
1 · Understandwhat's really being asked

A table lists how many students like roses, tulips (11), lilies (7), and daisies (13), with a total of 51. First find the missing rose count, then decide how many vertical grid squares a bar graph needs if one square stands for 5 students.

Givens
  • Tulip = 11, Lily = 7, Daisy = 13 students
  • Total = 51 students
  • One vertical grid square represents 5 students
Unknowns
  • The number of students who like roses
  • The least number of vertical grid squares the scale must have
Constraints
  • The scale must reach at least the largest single value
  • Each grid square stands for exactly 5 students
2 · Planchoose the strategy

#7 Identify Subproblems · also uses: #8 Analyze the Units

This is a two-step task: first recover the missing value from the total (a subtraction subproblem), then convert the largest value into grid squares using the 'students per square' unit.

3 · Execute3 carry out the plan

1Find the rose count

#7 Identify Subproblems 3.MD.B.3
Subtract the three known categories from the total to get the number of students who like roses.
51(11+7+13)=5131=2051 - (11 + 7 + 13) = 51 - 31 = 20
A total is the sum of its parts, so the missing part is the total minus the known parts.

2Find the largest value

#7 Identify Subproblems 3.MD.B.3
Compare the four counts: 20 (rose), 11 (tulip), 7 (lily), 13 (daisy). The largest is 20, so the scale must reach at least 20 students.
max(20,11,7,13)=20\max(20, 11, 7, 13) = 20
The tallest bar sets how high the scale must go.

3Convert students to grid squares

#8 Analyze the Units 3.MD.B.3
Each grid square is worth 5 students, so divide the largest value by 5 to find how many squares are needed.
20÷5=420 \div 5 = 4
If one square holds 5 students, then 20 students fill 4 squares exactly.
Answer: 4 squares
4 · Reviewdoes it hold up?

4 squares at 5 students each reach 20 students, matching the largest value, and 20 is bigger than every other count, so 4 squares is the smallest scale that fits.

Another way: Guess and check (tool 6): 3 squares reach only 15 students, too short for 20; 4 squares reach 20, which works, confirming 4 is the least.

Standardsmin grade 3
  • 3.MD.B.3 Draw and interpret scaled picture graphs and bar graphs — Choosing a vertical scale that fits the largest data value and counting the needed grid squares
💡Takeaway. This only needs Grade 3 bar-graph sense: find the biggest value, then count squares worth 5 each!
Variant 3 medium answer: 7 squares

Representative Problem

The table shows the favorite flowers of the students at Mia's school. If this table is drawn as a bar graph in which one vertical grid square represents 33 students, find the least number of vertical grid squares the scale must have.

Table "Favorite Flower":

Flower Rose Tulip Lily Daisy Total
Number of students (?) 1313 99 1717 6060
  • (Number of students who like roses) == [ ] (13+9+17)=- (13 + 9 + 17) = [ ] (students)
  • Since [ ] students like roses, the vertical scale must reach at least [ ] students.
  • If one vertical grid square represents 33 students, the vertical scale needs at least [ ] squares.
Show solution
1 · Understandwhat's really being asked

A table lists how many students like roses, tulips (13), lilies (9), and daisies (17), with a total of 60. First find the missing rose count, then decide how many vertical grid squares a bar graph needs if one square stands for 3 students.

Givens
  • Tulip = 13, Lily = 9, Daisy = 17 students
  • Total = 60 students
  • One vertical grid square represents 3 students
Unknowns
  • The number of students who like roses
  • The least number of vertical grid squares the scale must have
Constraints
  • The scale must reach at least the largest single value
  • Each grid square stands for exactly 3 students
2 · Planchoose the strategy

#7 Identify Subproblems · also uses: #8 Analyze the Units

This is a two-step task: first recover the missing value from the total (a subtraction subproblem), then convert the largest value into grid squares using the 'students per square' unit.

3 · Execute3 carry out the plan

1Find the rose count

#7 Identify Subproblems 3.MD.B.3
Subtract the three known categories from the total to get the number of students who like roses.
60(13+9+17)=6039=2160 - (13 + 9 + 17) = 60 - 39 = 21
A total is the sum of its parts, so the missing part is the total minus the known parts.

2Find the largest value

#7 Identify Subproblems 3.MD.B.3
Compare the four counts: 21 (rose), 13 (tulip), 9 (lily), 17 (daisy). The largest is 21, so the scale must reach at least 21 students.
max(21,13,9,17)=21\max(21, 13, 9, 17) = 21
The tallest bar sets how high the scale must go.

3Convert students to grid squares

#8 Analyze the Units 3.MD.B.3
Each grid square is worth 3 students, so divide the largest value by 3 to find how many squares are needed.
21÷3=721 \div 3 = 7
If one square holds 3 students, then 21 students fill 7 squares exactly.
Answer: 7 squares
4 · Reviewdoes it hold up?

7 squares at 3 students each reach 21 students, matching the largest value, and 21 is bigger than every other count, so 7 squares is the smallest scale that fits.

Another way: Guess and check (tool 6): 6 squares reach only 18 students, too short for 21; 7 squares reach 21, which works, confirming 7 is the least.

Standardsmin grade 3
  • 3.MD.B.3 Draw and interpret scaled picture graphs and bar graphs — Choosing a vertical scale that fits the largest data value and counting the needed grid squares
💡Takeaway. This only needs Grade 3 bar-graph sense: find the biggest value, then count squares worth 3 each!
Variant 4 easy answer: 6 squares

Representative Problem

The table shows the favorite flowers of the students at Mia's school. If this table is drawn as a bar graph in which one vertical grid square represents 44 students, find the least number of vertical grid squares the scale must have.

Table "Favorite Flower":

Flower Rose Tulip Lily Daisy Total
Number of students (?) 1212 88 1616 6060
  • (Number of students who like roses) == [ ] (12+8+16)=- (12 + 8 + 16) = [ ] (students)
  • Since [ ] students like roses, the vertical scale must reach at least [ ] students.
  • If one vertical grid square represents 44 students, the vertical scale needs at least [ ] squares.
Show solution
1 · Understandwhat's really being asked

A table lists how many students like roses, tulips (12), lilies (8), and daisies (16), with a total of 60. First find the missing rose count, then decide how many vertical grid squares a bar graph needs if one square stands for 4 students.

Givens
  • Tulip = 12, Lily = 8, Daisy = 16 students
  • Total = 60 students
  • One vertical grid square represents 4 students
Unknowns
  • The number of students who like roses
  • The least number of vertical grid squares the scale must have
Constraints
  • The scale must reach at least the largest single value
  • Each grid square stands for exactly 4 students
2 · Planchoose the strategy

#7 Identify Subproblems · also uses: #8 Analyze the Units

This is a two-step task: first recover the missing value from the total (a subtraction subproblem), then convert the largest value into grid squares using the 'students per square' unit.

3 · Execute3 carry out the plan

1Find the rose count

#7 Identify Subproblems 3.MD.B.3
Subtract the three known categories from the total to get the number of students who like roses.
60(12+8+16)=6036=2460 - (12 + 8 + 16) = 60 - 36 = 24
A total is the sum of its parts, so the missing part is the total minus the known parts.

2Find the largest value

#7 Identify Subproblems 3.MD.B.3
Compare the four counts: 24 (rose), 12 (tulip), 8 (lily), 16 (daisy). The largest is 24, so the scale must reach at least 24 students.
max(24,12,8,16)=24\max(24, 12, 8, 16) = 24
The tallest bar sets how high the scale must go.

3Convert students to grid squares

#8 Analyze the Units 3.MD.B.3
Each grid square is worth 4 students, so divide the largest value by 4 to find how many squares are needed.
24÷4=624 \div 4 = 6
If one square holds 4 students, then 24 students fill 6 squares exactly.
Answer: 6 squares
4 · Reviewdoes it hold up?

6 squares at 4 students each reach 24 students, matching the largest value, and 24 is bigger than every other count, so 6 squares is the smallest scale that fits.

Another way: Guess and check (tool 6): 5 squares reach only 20 students, too short for 24; 6 squares reach 24, which works, confirming 6 is the least.

Standardsmin grade 3
  • 3.MD.B.3 Draw and interpret scaled picture graphs and bar graphs — Choosing a vertical scale that fits the largest data value and counting the needed grid squares
💡Takeaway. This only needs Grade 3 bar-graph sense: find the biggest value, then count squares worth 4 each!
Variant 5 medium answer: 11 squares

Representative Problem

The table shows the favorite flowers of the students at Mia's school. If this table is drawn as a bar graph in which one vertical grid square represents 22 students, find the least number of vertical grid squares the scale must have.

Table "Favorite Flower":

Flower Rose Tulip Lily Daisy Total
Number of students (?) 1818 1010 1414 6464
  • (Number of students who like roses) == [ ] (18+10+14)=- (18 + 10 + 14) = [ ] (students)
  • Since [ ] students like roses, the vertical scale must reach at least [ ] students.
  • If one vertical grid square represents 22 students, the vertical scale needs at least [ ] squares.
Show solution
1 · Understandwhat's really being asked

A table lists how many students like roses, tulips (18), lilies (10), and daisies (14), with a total of 64. First find the missing rose count, then decide how many vertical grid squares a bar graph needs if one square stands for 2 students.

Givens
  • Tulip = 18, Lily = 10, Daisy = 14 students
  • Total = 64 students
  • One vertical grid square represents 2 students
Unknowns
  • The number of students who like roses
  • The least number of vertical grid squares the scale must have
Constraints
  • The scale must reach at least the largest single value
  • Each grid square stands for exactly 2 students
2 · Planchoose the strategy

#7 Identify Subproblems · also uses: #8 Analyze the Units

This is a two-step task: first recover the missing value from the total (a subtraction subproblem), then convert the largest value into grid squares using the 'students per square' unit.

3 · Execute3 carry out the plan

1Find the rose count

#7 Identify Subproblems 3.MD.B.3
Subtract the three known categories from the total to get the number of students who like roses.
64(18+10+14)=6442=2264 - (18 + 10 + 14) = 64 - 42 = 22
A total is the sum of its parts, so the missing part is the total minus the known parts.

2Find the largest value

#7 Identify Subproblems 3.MD.B.3
Compare the four counts: 22 (rose), 18 (tulip), 10 (lily), 14 (daisy). The largest is 22, so the scale must reach at least 22 students.
max(22,18,10,14)=22\max(22, 18, 10, 14) = 22
The tallest bar sets how high the scale must go.

3Convert students to grid squares

#8 Analyze the Units 3.MD.B.3
Each grid square is worth 2 students, so divide the largest value by 2 to find how many squares are needed.
22÷2=1122 \div 2 = 11
If one square holds 2 students, then 22 students fill 11 squares exactly.
Answer: 11 squares
4 · Reviewdoes it hold up?

11 squares at 2 students each reach 22 students, matching the largest value, and 22 is bigger than every other count, so 11 squares is the smallest scale that fits.

Another way: Guess and check (tool 6): 10 squares reach only 20 students, too short for 22; 11 squares reach 22, which works, confirming 11 is the least.

Standardsmin grade 3
  • 3.MD.B.3 Draw and interpret scaled picture graphs and bar graphs — Choosing a vertical scale that fits the largest data value and counting the needed grid squares
💡Takeaway. This only needs Grade 3 bar-graph sense: find the biggest value, then count squares worth 2 each!
Variant 6 medium answer: 5 squares

Representative Problem

The table shows the favorite flowers of the students at Mia's school. If this table is drawn as a bar graph in which one vertical grid square represents 55 students, find the least number of vertical grid squares the scale must have.

Table "Favorite Flower":

Flower Rose Tulip Lily Daisy Total
Number of students (?) 1515 99 2121 7070
  • (Number of students who like roses) == [ ] (15+9+21)=- (15 + 9 + 21) = [ ] (students)
  • Since [ ] students like roses, the vertical scale must reach at least [ ] students.
  • If one vertical grid square represents 55 students, the vertical scale needs at least [ ] squares.
Show solution
1 · Understandwhat's really being asked

A table lists how many students like roses, tulips (15), lilies (9), and daisies (21), with a total of 70. First find the missing rose count, then decide how many vertical grid squares a bar graph needs if one square stands for 5 students.

Givens
  • Tulip = 15, Lily = 9, Daisy = 21 students
  • Total = 70 students
  • One vertical grid square represents 5 students
Unknowns
  • The number of students who like roses
  • The least number of vertical grid squares the scale must have
Constraints
  • The scale must reach at least the largest single value
  • Each grid square stands for exactly 5 students
2 · Planchoose the strategy

#7 Identify Subproblems · also uses: #8 Analyze the Units

This is a two-step task: first recover the missing value from the total (a subtraction subproblem), then convert the largest value into grid squares using the 'students per square' unit.

3 · Execute3 carry out the plan

1Find the rose count

#7 Identify Subproblems 3.MD.B.3
Subtract the three known categories from the total to get the number of students who like roses.
70(15+9+21)=7045=2570 - (15 + 9 + 21) = 70 - 45 = 25
A total is the sum of its parts, so the missing part is the total minus the known parts.

2Find the largest value

#7 Identify Subproblems 3.MD.B.3
Compare the four counts: 25 (rose), 15 (tulip), 9 (lily), 21 (daisy). The largest is 25, so the scale must reach at least 25 students.
max(25,15,9,21)=25\max(25, 15, 9, 21) = 25
The tallest bar sets how high the scale must go.

3Convert students to grid squares

#8 Analyze the Units 3.MD.B.3
Each grid square is worth 5 students, so divide the largest value by 5 to find how many squares are needed.
25÷5=525 \div 5 = 5
If one square holds 5 students, then 25 students fill 5 squares exactly.
Answer: 5 squares
4 · Reviewdoes it hold up?

5 squares at 5 students each reach 25 students, matching the largest value, and 25 is bigger than every other count, so 5 squares is the smallest scale that fits.

Another way: Guess and check (tool 6): 4 squares reach only 20 students, too short for 25; 5 squares reach 25, which works, confirming 5 is the least.

Standardsmin grade 3
  • 3.MD.B.3 Draw and interpret scaled picture graphs and bar graphs — Choosing a vertical scale that fits the largest data value and counting the needed grid squares
💡Takeaway. This only needs Grade 3 bar-graph sense: find the biggest value, then count squares worth 5 each!
Variant 7 medium answer: 15 squares

Representative Problem

The table shows the favorite flowers of the students at Mia's school. If this table is drawn as a bar graph in which one vertical grid square represents 22 students, find the least number of vertical grid squares the scale must have.

Table "Favorite Flower":

Flower Rose Tulip Lily Daisy Total
Number of students (?) 1616 1212 2020 7878
  • (Number of students who like roses) == [ ] (16+12+20)=- (16 + 12 + 20) = [ ] (students)
  • Since [ ] students like roses, the vertical scale must reach at least [ ] students.
  • If one vertical grid square represents 22 students, the vertical scale needs at least [ ] squares.
Show solution
1 · Understandwhat's really being asked

A table lists how many students like roses, tulips (16), lilies (12), and daisies (20), with a total of 78. First find the missing rose count, then decide how many vertical grid squares a bar graph needs if one square stands for 2 students.

Givens
  • Tulip = 16, Lily = 12, Daisy = 20 students
  • Total = 78 students
  • One vertical grid square represents 2 students
Unknowns
  • The number of students who like roses
  • The least number of vertical grid squares the scale must have
Constraints
  • The scale must reach at least the largest single value
  • Each grid square stands for exactly 2 students
2 · Planchoose the strategy

#7 Identify Subproblems · also uses: #8 Analyze the Units

This is a two-step task: first recover the missing value from the total (a subtraction subproblem), then convert the largest value into grid squares using the 'students per square' unit.

3 · Execute3 carry out the plan

1Find the rose count

#7 Identify Subproblems 3.MD.B.3
Subtract the three known categories from the total to get the number of students who like roses.
78(16+12+20)=7848=3078 - (16 + 12 + 20) = 78 - 48 = 30
A total is the sum of its parts, so the missing part is the total minus the known parts.

2Find the largest value

#7 Identify Subproblems 3.MD.B.3
Compare the four counts: 30 (rose), 16 (tulip), 12 (lily), 20 (daisy). The largest is 30, so the scale must reach at least 30 students.
max(30,16,12,20)=30\max(30, 16, 12, 20) = 30
The tallest bar sets how high the scale must go.

3Convert students to grid squares

#8 Analyze the Units 3.MD.B.3
Each grid square is worth 2 students, so divide the largest value by 2 to find how many squares are needed.
30÷2=1530 \div 2 = 15
If one square holds 2 students, then 30 students fill 15 squares exactly.
Answer: 15 squares
4 · Reviewdoes it hold up?

15 squares at 2 students each reach 30 students, matching the largest value, and 30 is bigger than every other count, so 15 squares is the smallest scale that fits.

Another way: Guess and check (tool 6): 14 squares reach only 28 students, too short for 30; 15 squares reach 30, which works, confirming 15 is the least.

Standardsmin grade 3
  • 3.MD.B.3 Draw and interpret scaled picture graphs and bar graphs — Choosing a vertical scale that fits the largest data value and counting the needed grid squares
💡Takeaway. This only needs Grade 3 bar-graph sense: find the biggest value, then count squares worth 2 each!
Variant 8 hard answer: 14 squares

Representative Problem

The table shows the favorite flowers of the students at Mia's school. If this table is drawn as a bar graph in which one vertical grid square represents 22 students, find the least number of vertical grid squares the scale must have.

Table "Favorite Flower":

Flower Rose Tulip Lily Daisy Total
Number of students (?) 2020 1414 1818 8080
  • (Number of students who like roses) == [ ] (20+14+18)=- (20 + 14 + 18) = [ ] (students)
  • Since [ ] students like roses, the vertical scale must reach at least [ ] students.
  • If one vertical grid square represents 22 students, the vertical scale needs at least [ ] squares.
Show solution
1 · Understandwhat's really being asked

A table lists how many students like roses, tulips (20), lilies (14), and daisies (18), with a total of 80. First find the missing rose count, then decide how many vertical grid squares a bar graph needs if one square stands for 2 students.

Givens
  • Tulip = 20, Lily = 14, Daisy = 18 students
  • Total = 80 students
  • One vertical grid square represents 2 students
Unknowns
  • The number of students who like roses
  • The least number of vertical grid squares the scale must have
Constraints
  • The scale must reach at least the largest single value
  • Each grid square stands for exactly 2 students
2 · Planchoose the strategy

#7 Identify Subproblems · also uses: #8 Analyze the Units

This is a two-step task: first recover the missing value from the total (a subtraction subproblem), then convert the largest value into grid squares using the 'students per square' unit.

3 · Execute3 carry out the plan

1Find the rose count

#7 Identify Subproblems 3.MD.B.3
Subtract the three known categories from the total to get the number of students who like roses.
80(20+14+18)=8052=2880 - (20 + 14 + 18) = 80 - 52 = 28
A total is the sum of its parts, so the missing part is the total minus the known parts.

2Find the largest value

#7 Identify Subproblems 3.MD.B.3
Compare the four counts: 28 (rose), 20 (tulip), 14 (lily), 18 (daisy). The largest is 28, so the scale must reach at least 28 students.
max(28,20,14,18)=28\max(28, 20, 14, 18) = 28
The tallest bar sets how high the scale must go.

3Convert students to grid squares

#8 Analyze the Units 3.MD.B.3
Each grid square is worth 2 students, so divide the largest value by 2 to find how many squares are needed.
28÷2=1428 \div 2 = 14
If one square holds 2 students, then 28 students fill 14 squares exactly.
Answer: 14 squares
4 · Reviewdoes it hold up?

14 squares at 2 students each reach 28 students, matching the largest value, and 28 is bigger than every other count, so 14 squares is the smallest scale that fits.

Another way: Guess and check (tool 6): 13 squares reach only 26 students, too short for 28; 14 squares reach 28, which works, confirming 14 is the least.

Standardsmin grade 3
  • 3.MD.B.3 Draw and interpret scaled picture graphs and bar graphs — Choosing a vertical scale that fits the largest data value and counting the needed grid squares
💡Takeaway. This only needs Grade 3 bar-graph sense: find the biggest value, then count squares worth 2 each!
Variant 9 hard answer: 17 squares

Representative Problem

The table shows the favorite flowers of the students at Mia's school. If this table is drawn as a bar graph in which one vertical grid square represents 22 students, find the least number of vertical grid squares the scale must have.

Table "Favorite Flower":

Flower Rose Tulip Lily Daisy Total
Number of students (?) 2222 1818 2626 100100
  • (Number of students who like roses) == [ ] (22+18+26)=- (22 + 18 + 26) = [ ] (students)
  • Since [ ] students like roses, the vertical scale must reach at least [ ] students.
  • If one vertical grid square represents 22 students, the vertical scale needs at least [ ] squares.
Show solution
1 · Understandwhat's really being asked

A table lists how many students like roses, tulips (22), lilies (18), and daisies (26), with a total of 100. First find the missing rose count, then decide how many vertical grid squares a bar graph needs if one square stands for 2 students.

Givens
  • Tulip = 22, Lily = 18, Daisy = 26 students
  • Total = 100 students
  • One vertical grid square represents 2 students
Unknowns
  • The number of students who like roses
  • The least number of vertical grid squares the scale must have
Constraints
  • The scale must reach at least the largest single value
  • Each grid square stands for exactly 2 students
2 · Planchoose the strategy

#7 Identify Subproblems · also uses: #8 Analyze the Units

This is a two-step task: first recover the missing value from the total (a subtraction subproblem), then convert the largest value into grid squares using the 'students per square' unit.

3 · Execute3 carry out the plan

1Find the rose count

#7 Identify Subproblems 3.MD.B.3
Subtract the three known categories from the total to get the number of students who like roses.
100(22+18+26)=10066=34100 - (22 + 18 + 26) = 100 - 66 = 34
A total is the sum of its parts, so the missing part is the total minus the known parts.

2Find the largest value

#7 Identify Subproblems 3.MD.B.3
Compare the four counts: 34 (rose), 22 (tulip), 18 (lily), 26 (daisy). The largest is 34, so the scale must reach at least 34 students.
max(34,22,18,26)=34\max(34, 22, 18, 26) = 34
The tallest bar sets how high the scale must go.

3Convert students to grid squares

#8 Analyze the Units 3.MD.B.3
Each grid square is worth 2 students, so divide the largest value by 2 to find how many squares are needed.
34÷2=1734 \div 2 = 17
If one square holds 2 students, then 34 students fill 17 squares exactly.
Answer: 17 squares
4 · Reviewdoes it hold up?

17 squares at 2 students each reach 34 students, matching the largest value, and 34 is bigger than every other count, so 17 squares is the smallest scale that fits.

Another way: Guess and check (tool 6): 16 squares reach only 32 students, too short for 34; 17 squares reach 34, which works, confirming 17 is the least.

Standardsmin grade 3
  • 3.MD.B.3 Draw and interpret scaled picture graphs and bar graphs — Choosing a vertical scale that fits the largest data value and counting the needed grid squares
💡Takeaway. This only needs Grade 3 bar-graph sense: find the biggest value, then count squares worth 2 each!
Variant 10 hard answer: 9 squares

Representative Problem

The table shows the favorite flowers of the students at Mia's school. If this table is drawn as a bar graph in which one vertical grid square represents 44 students, find the least number of vertical grid squares the scale must have.

Table "Favorite Flower":

Flower Rose Tulip Lily Daisy Total
Number of students (?) 2424 1616 2828 104104
  • (Number of students who like roses) == [ ] (24+16+28)=- (24 + 16 + 28) = [ ] (students)
  • Since [ ] students like roses, the vertical scale must reach at least [ ] students.
  • If one vertical grid square represents 44 students, the vertical scale needs at least [ ] squares.
Show solution
1 · Understandwhat's really being asked

A table lists how many students like roses, tulips (24), lilies (16), and daisies (28), with a total of 104. First find the missing rose count, then decide how many vertical grid squares a bar graph needs if one square stands for 4 students.

Givens
  • Tulip = 24, Lily = 16, Daisy = 28 students
  • Total = 104 students
  • One vertical grid square represents 4 students
Unknowns
  • The number of students who like roses
  • The least number of vertical grid squares the scale must have
Constraints
  • The scale must reach at least the largest single value
  • Each grid square stands for exactly 4 students
2 · Planchoose the strategy

#7 Identify Subproblems · also uses: #8 Analyze the Units

This is a two-step task: first recover the missing value from the total (a subtraction subproblem), then convert the largest value into grid squares using the 'students per square' unit.

3 · Execute3 carry out the plan

1Find the rose count

#7 Identify Subproblems 3.MD.B.3
Subtract the three known categories from the total to get the number of students who like roses.
104(24+16+28)=10468=36104 - (24 + 16 + 28) = 104 - 68 = 36
A total is the sum of its parts, so the missing part is the total minus the known parts.

2Find the largest value

#7 Identify Subproblems 3.MD.B.3
Compare the four counts: 36 (rose), 24 (tulip), 16 (lily), 28 (daisy). The largest is 36, so the scale must reach at least 36 students.
max(36,24,16,28)=36\max(36, 24, 16, 28) = 36
The tallest bar sets how high the scale must go.

3Convert students to grid squares

#8 Analyze the Units 3.MD.B.3
Each grid square is worth 4 students, so divide the largest value by 4 to find how many squares are needed.
36÷4=936 \div 4 = 9
If one square holds 4 students, then 36 students fill 9 squares exactly.
Answer: 9 squares
4 · Reviewdoes it hold up?

9 squares at 4 students each reach 36 students, matching the largest value, and 36 is bigger than every other count, so 9 squares is the smallest scale that fits.

Another way: Guess and check (tool 6): 8 squares reach only 32 students, too short for 36; 9 squares reach 36, which works, confirming 9 is the least.

Standardsmin grade 3
  • 3.MD.B.3 Draw and interpret scaled picture graphs and bar graphs — Choosing a vertical scale that fits the largest data value and counting the needed grid squares
💡Takeaway. This only needs Grade 3 bar-graph sense: find the biggest value, then count squares worth 4 each!