Recover missing digits from column carries
3.NBT.A.33.OA.B.5
Generated variants — 10
In the multiplication below, find the digits and .
Here is the tens digit and is the ones digit of the two-digit number being multiplied. The two-digit number times equals .
Show solution
1 · Understandwhat's really being asked
A two-digit number with tens digit A and ones digit B is multiplied by 2, and the product is 126. We must find the digits A and B.
Givens
- The two-digit number is written A B (A tens, B ones)
- The two-digit number times 2 equals 126
Unknowns
- The tens digit A
- The ones digit B
Constraints
- A and B are single digits (0-9), and A is not 0 since A B is a two-digit number
2 · Planchoose the strategy
#11 Work Backwards
The result of the multiplication is given, so we undo it: dividing 126 by 2 recovers the two-digit number, and reading its digits gives A and B. A quick column check confirms the carry.
3 · Execute3 carry out the plan
1Undo the multiplication
2Read off the digits
3Check the column multiplication
4 · Reviewdoes it hold up?
63 times 2 = 126 exactly, and both A=6 and B=3 are valid single digits with A not zero, so the two-digit number 63 is legitimate.
Standardsmin grade 3
3.OA.A.3Solve multiplication and division word problems within 100 — Dividing 126 by 2 to recover the two-digit factor3.NBT.A.3Multiply one-digit whole numbers by multiples of 10 — Using place value to read the tens digit A and ones digit B3.OA.B.5Apply properties of operations as strategies to multiply and divide — Checking the column multiplication with carrying
In the multiplication below, find the digits and .
Here is the tens digit and is the ones digit of the two-digit number being multiplied. The two-digit number times equals .
Show solution
1 · Understandwhat's really being asked
A two-digit number with tens digit A and ones digit B is multiplied by 5, and the product is 145. We must find the digits A and B.
Givens
- The two-digit number is written A B (A tens, B ones)
- The two-digit number times 5 equals 145
Unknowns
- The tens digit A
- The ones digit B
Constraints
- A and B are single digits (0-9), and A is not 0 since A B is a two-digit number
2 · Planchoose the strategy
#11 Work Backwards
The result of the multiplication is given, so we undo it: dividing 145 by 5 recovers the two-digit number, and reading its digits gives A and B. A quick column check confirms the carry.
3 · Execute3 carry out the plan
1Undo the multiplication
2Read off the digits
3Check the column multiplication
4 · Reviewdoes it hold up?
29 times 5 = 145 exactly, and both A=2 and B=9 are valid single digits with A not zero, so the two-digit number 29 is legitimate.
Standardsmin grade 3
3.OA.A.3Solve multiplication and division word problems within 100 — Dividing 145 by 5 to recover the two-digit factor3.NBT.A.3Multiply one-digit whole numbers by multiples of 10 — Using place value to read the tens digit A and ones digit B3.OA.B.5Apply properties of operations as strategies to multiply and divide — Checking the column multiplication with carrying
In the multiplication below, find the digits and .
Here is the tens digit and is the ones digit of the two-digit number being multiplied. The two-digit number times equals .
Show solution
1 · Understandwhat's really being asked
A two-digit number with tens digit A and ones digit B is multiplied by 4, and the product is 148. We must find the digits A and B.
Givens
- The two-digit number is written A B (A tens, B ones)
- The two-digit number times 4 equals 148
Unknowns
- The tens digit A
- The ones digit B
Constraints
- A and B are single digits (0-9), and A is not 0 since A B is a two-digit number
2 · Planchoose the strategy
#11 Work Backwards
The result of the multiplication is given, so we undo it: dividing 148 by 4 recovers the two-digit number, and reading its digits gives A and B. A quick column check confirms the carry.
3 · Execute3 carry out the plan
1Undo the multiplication
2Read off the digits
3Check the column multiplication
4 · Reviewdoes it hold up?
37 times 4 = 148 exactly, and both A=3 and B=7 are valid single digits with A not zero, so the two-digit number 37 is legitimate.
Standardsmin grade 3
3.OA.A.3Solve multiplication and division word problems within 100 — Dividing 148 by 4 to recover the two-digit factor3.NBT.A.3Multiply one-digit whole numbers by multiples of 10 — Using place value to read the tens digit A and ones digit B3.OA.B.5Apply properties of operations as strategies to multiply and divide — Checking the column multiplication with carrying
In the multiplication below, find the digits and .
Here is the tens digit and is the ones digit of the two-digit number being multiplied. The two-digit number times equals .
Show solution
1 · Understandwhat's really being asked
A two-digit number with tens digit A and ones digit B is multiplied by 3, and the product is 156. We must find the digits A and B.
Givens
- The two-digit number is written A B (A tens, B ones)
- The two-digit number times 3 equals 156
Unknowns
- The tens digit A
- The ones digit B
Constraints
- A and B are single digits (0-9), and A is not 0 since A B is a two-digit number
2 · Planchoose the strategy
#11 Work Backwards
The result of the multiplication is given, so we undo it: dividing 156 by 3 recovers the two-digit number, and reading its digits gives A and B. A quick column check confirms the carry.
3 · Execute3 carry out the plan
1Undo the multiplication
2Read off the digits
3Check the column multiplication
4 · Reviewdoes it hold up?
52 times 3 = 156 exactly, and both A=5 and B=2 are valid single digits with A not zero, so the two-digit number 52 is legitimate.
Standardsmin grade 3
3.OA.A.3Solve multiplication and division word problems within 100 — Dividing 156 by 3 to recover the two-digit factor3.NBT.A.3Multiply one-digit whole numbers by multiples of 10 — Using place value to read the tens digit A and ones digit B3.OA.B.5Apply properties of operations as strategies to multiply and divide — Checking the column multiplication with carrying
In the multiplication below, find the digits and .
Here is the tens digit and is the ones digit of the two-digit number being multiplied. The two-digit number times equals .
Show solution
1 · Understandwhat's really being asked
A two-digit number with tens digit A and ones digit B is multiplied by 8, and the product is 216. We must find the digits A and B.
Givens
- The two-digit number is written A B (A tens, B ones)
- The two-digit number times 8 equals 216
Unknowns
- The tens digit A
- The ones digit B
Constraints
- A and B are single digits (0-9), and A is not 0 since A B is a two-digit number
2 · Planchoose the strategy
#11 Work Backwards
The result of the multiplication is given, so we undo it: dividing 216 by 8 recovers the two-digit number, and reading its digits gives A and B. A quick column check confirms the carry.
3 · Execute3 carry out the plan
1Undo the multiplication
2Read off the digits
3Check the column multiplication
4 · Reviewdoes it hold up?
27 times 8 = 216 exactly, and both A=2 and B=7 are valid single digits with A not zero, so the two-digit number 27 is legitimate.
Standardsmin grade 3
3.OA.A.3Solve multiplication and division word problems within 100 — Dividing 216 by 8 to recover the two-digit factor3.NBT.A.3Multiply one-digit whole numbers by multiples of 10 — Using place value to read the tens digit A and ones digit B3.OA.B.5Apply properties of operations as strategies to multiply and divide — Checking the column multiplication with carrying
In the multiplication below, find the digits and .
Here is the tens digit and is the ones digit of the two-digit number being multiplied. The two-digit number times equals .
Show solution
1 · Understandwhat's really being asked
A two-digit number with tens digit A and ones digit B is multiplied by 4, and the product is 232. We must find the digits A and B.
Givens
- The two-digit number is written A B (A tens, B ones)
- The two-digit number times 4 equals 232
Unknowns
- The tens digit A
- The ones digit B
Constraints
- A and B are single digits (0-9), and A is not 0 since A B is a two-digit number
2 · Planchoose the strategy
#11 Work Backwards
The result of the multiplication is given, so we undo it: dividing 232 by 4 recovers the two-digit number, and reading its digits gives A and B. A quick column check confirms the carry.
3 · Execute3 carry out the plan
1Undo the multiplication
2Read off the digits
3Check the column multiplication
4 · Reviewdoes it hold up?
58 times 4 = 232 exactly, and both A=5 and B=8 are valid single digits with A not zero, so the two-digit number 58 is legitimate.
Standardsmin grade 3
3.OA.A.3Solve multiplication and division word problems within 100 — Dividing 232 by 4 to recover the two-digit factor3.NBT.A.3Multiply one-digit whole numbers by multiples of 10 — Using place value to read the tens digit A and ones digit B3.OA.B.5Apply properties of operations as strategies to multiply and divide — Checking the column multiplication with carrying
In the multiplication below, find the digits and .
Here is the tens digit and is the ones digit of the two-digit number being multiplied. The two-digit number times equals .
Show solution
1 · Understandwhat's really being asked
A two-digit number with tens digit A and ones digit B is multiplied by 3, and the product is 255. We must find the digits A and B.
Givens
- The two-digit number is written A B (A tens, B ones)
- The two-digit number times 3 equals 255
Unknowns
- The tens digit A
- The ones digit B
Constraints
- A and B are single digits (0-9), and A is not 0 since A B is a two-digit number
2 · Planchoose the strategy
#11 Work Backwards
The result of the multiplication is given, so we undo it: dividing 255 by 3 recovers the two-digit number, and reading its digits gives A and B. A quick column check confirms the carry.
3 · Execute3 carry out the plan
1Undo the multiplication
2Read off the digits
3Check the column multiplication
4 · Reviewdoes it hold up?
85 times 3 = 255 exactly, and both A=8 and B=5 are valid single digits with A not zero, so the two-digit number 85 is legitimate.
Standardsmin grade 3
3.OA.A.3Solve multiplication and division word problems within 100 — Dividing 255 by 3 to recover the two-digit factor3.NBT.A.3Multiply one-digit whole numbers by multiples of 10 — Using place value to read the tens digit A and ones digit B3.OA.B.5Apply properties of operations as strategies to multiply and divide — Checking the column multiplication with carrying
In the multiplication below, find the digits and .
Here is the tens digit and is the ones digit of the two-digit number being multiplied. The two-digit number times equals .
Show solution
1 · Understandwhat's really being asked
A two-digit number with tens digit A and ones digit B is multiplied by 6, and the product is 288. We must find the digits A and B.
Givens
- The two-digit number is written A B (A tens, B ones)
- The two-digit number times 6 equals 288
Unknowns
- The tens digit A
- The ones digit B
Constraints
- A and B are single digits (0-9), and A is not 0 since A B is a two-digit number
2 · Planchoose the strategy
#11 Work Backwards
The result of the multiplication is given, so we undo it: dividing 288 by 6 recovers the two-digit number, and reading its digits gives A and B. A quick column check confirms the carry.
3 · Execute3 carry out the plan
1Undo the multiplication
2Read off the digits
3Check the column multiplication
4 · Reviewdoes it hold up?
48 times 6 = 288 exactly, and both A=4 and B=8 are valid single digits with A not zero, so the two-digit number 48 is legitimate.
Standardsmin grade 3
3.OA.A.3Solve multiplication and division word problems within 100 — Dividing 288 by 6 to recover the two-digit factor3.NBT.A.3Multiply one-digit whole numbers by multiples of 10 — Using place value to read the tens digit A and ones digit B3.OA.B.5Apply properties of operations as strategies to multiply and divide — Checking the column multiplication with carrying
In the multiplication below, find the digits and .
Here is the tens digit and is the ones digit of the two-digit number being multiplied. The two-digit number times equals .
Show solution
1 · Understandwhat's really being asked
A two-digit number with tens digit A and ones digit B is multiplied by 7, and the product is 322. We must find the digits A and B.
Givens
- The two-digit number is written A B (A tens, B ones)
- The two-digit number times 7 equals 322
Unknowns
- The tens digit A
- The ones digit B
Constraints
- A and B are single digits (0-9), and A is not 0 since A B is a two-digit number
2 · Planchoose the strategy
#11 Work Backwards
The result of the multiplication is given, so we undo it: dividing 322 by 7 recovers the two-digit number, and reading its digits gives A and B. A quick column check confirms the carry.
3 · Execute3 carry out the plan
1Undo the multiplication
2Read off the digits
3Check the column multiplication
4 · Reviewdoes it hold up?
46 times 7 = 322 exactly, and both A=4 and B=6 are valid single digits with A not zero, so the two-digit number 46 is legitimate.
Standardsmin grade 3
3.OA.A.3Solve multiplication and division word problems within 100 — Dividing 322 by 7 to recover the two-digit factor3.NBT.A.3Multiply one-digit whole numbers by multiples of 10 — Using place value to read the tens digit A and ones digit B3.OA.B.5Apply properties of operations as strategies to multiply and divide — Checking the column multiplication with carrying
In the multiplication below, find the digits and .
Here is the tens digit and is the ones digit of the two-digit number being multiplied. The two-digit number times equals .
Show solution
1 · Understandwhat's really being asked
A two-digit number with tens digit A and ones digit B is multiplied by 6, and the product is 444. We must find the digits A and B.
Givens
- The two-digit number is written A B (A tens, B ones)
- The two-digit number times 6 equals 444
Unknowns
- The tens digit A
- The ones digit B
Constraints
- A and B are single digits (0-9), and A is not 0 since A B is a two-digit number
2 · Planchoose the strategy
#11 Work Backwards
The result of the multiplication is given, so we undo it: dividing 444 by 6 recovers the two-digit number, and reading its digits gives A and B. A quick column check confirms the carry.
3 · Execute3 carry out the plan
1Undo the multiplication
2Read off the digits
3Check the column multiplication
4 · Reviewdoes it hold up?
74 times 6 = 444 exactly, and both A=7 and B=4 are valid single digits with A not zero, so the two-digit number 74 is legitimate.
Standardsmin grade 3
3.OA.A.3Solve multiplication and division word problems within 100 — Dividing 444 by 6 to recover the two-digit factor3.NBT.A.3Multiply one-digit whole numbers by multiples of 10 — Using place value to read the tens digit A and ones digit B3.OA.B.5Apply properties of operations as strategies to multiply and divide — Checking the column multiplication with carrying