All the solutions provided in **McGraw Hill My Math Grade 2 Answer Key PDF Chapter 7 Lesson 5 Regroup Hundreds **will give you a clear idea of the concepts.

## McGraw-Hill My Math Grade 2 Answer Key Chapter 7 Lesson 5 Regroup Hundreds

**Explore and Explain**

_____________ pieces of macaroni

**Teacher Directions:** Use base-ten blocks to solve. Gwen put 214 pieces of macaroni on her picture in art class. 120 pieces fell off. How many pieces of macaroni are still on the picture? Draw the blocks you used. Write the number.

Answer:

94 pieces of macaroni.

Explanation:

Given,

Gwen put pieces of macaroni on her picture in art class 214.

In this 120 pieces fell off.

We need to find out how many pieces of macaroni are still in the picture.

The difference between the pieces – pieces fell off = 214 – 120 = 94 pieces

Hence there are 94 pieces of macaroni are still in the picture.

**See and Show**

Find 539 – 285.

Step 1:

Subtract the ones.

Step 2:

Subtract the tens. You cannot subtract 8 from 3. Regroup 1 hundred as 10 tens.

Step 3:

Subtract the hundreds.

**Use Work Mat 7 and base-ten blocks. Subtract.**

Question 1.

Answer:

371

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 8 – 7 = 1 ones.

3. Now subtract the tens column. Here 9 > 6 so we cannot subtract 9 from 6. Therefore regroup 5 hundred and 16 tens = 4 hundred and 16 tens. Subtract 16 – 9 = 7 tens.

4. Next subtract the hundreds column = 4 – 1 = 3 hundreds.

Question 2.

Answer:

186

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 8 – 2 = 6 ones.

3. Now subtract the tens column. Here 4 > 2 so we cannot subtract 4 from 2. Therefore regroup 6 hundred and 2 tens = 5 hundred and 12 tens. Subtract 12 – 4 = 8 tens.

4. Next subtract the hundreds column = 5 – 4 = 1 hundreds.

**Talk Math** How do you know when to regroup?

Answer:

We can make regroup the numbers when performing operations such as addition or subtraction. If the digit in the one’s place on the bottom is greater than the digit in the one’s place on the top, we have to regroup from the tens place to the one’s place.

**On My Own**

**Use Work Mat 7 and base-ten blocks. Subtract.**

Question 3.

Answer:

191

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 6 – 5 = 1 ones.

3. Now subtract the tens column. Here 9 > 8 so we cannot subtract 9 from 8. Therefore regroup 5 hundred and 8 tens = 4 hundred and 18 tens. Subtract 18 – 9 = 9 tens.

4. Next subtract the hundreds column = 4 – 2 = 1 hundreds.

Question 4.

Answer:

595

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 8 – 3 = 5 ones.

3. Now subtract the tens column. Here 4 > 3 so we cannot subtract 4 from 3. Therefore regroup 6 hundred and 13 tens = 5 hundred and 13 tens. Subtract 13 – 4 = 9 tens.

4. Now bring down the remaining number i.e 5. The answer to this problem is 5.

Question 5.

Answer:

390

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 9 – 9 = 0 ones.

3. Now subtract the tens column. Here 6 > 5 so we cannot subtract 6 from 5. Therefore regroup 3 hundred and 15 tens = 3 hundred and 15 tens. Subtract 15 – 6 = 9 tens.

4. Now bring down the remaining number which is 3. The answer to this problem is 390.

Question 6.

Answer:

198

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 9 – 1 = 8 ones.

3. Now subtract the tens column. Here 4 > 3 so we cannot subtract 4 from 3. Therefore regroup 7 hundred and 3 tens = 6 hundred and 13 tens. Subtract 13 – 4 = 9 tens.

4. Next subtract the hundreds column = 6 – 5 = 1 hundreds.

Question 7.

Answer:

580

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 7 – 7 = 0 ones.

3. Now subtract the tens column. Here 4 > 2 so we cannot subtract 4 from 2. Therefore regroup 7 hundred and 2 tens = 7 hundred and 12 tens. Subtract 12 – 4 = 8 tens.

4. Next subtract the hundreds column = 7 – 2 = 5 hundreds.

Question 8.

Answer:

602

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 8 – 6 = 2 ones.

3. Now subtract the tens column. Subtract 3 – 3 = 0.

4. Now bring down the remaining 6 down. Hence the answer to this problem is 602.

Question 9.

Answer:

62

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 2 – 0 = 2 ones.

3. Now subtract the tens column. Here 7 > 3 so we cannot subtract 7 from 3. Therefore regroup 2 hundred and 3 tens = 1 hundred and 13 tens. Subtract 13 – 7 = 6 tens.

4. Next subtract the hundreds column = 1 – 1 = 0 hundreds.

Question 10.

Answer:

476

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 8 – 2 = 6 ones.

3. Now subtract the tens column. Here 7 > 4 so we cannot subtract 7 from 4. Therefore regroup 9 hundred and 4 tens = 8 hundred and 14 tens. Subtract 14 – 7 = 7 tens.

4. Next subtract the hundreds column = 8 – 4 = 4 hundred.

Question 11.

Answer:

293

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 5 – 2 = 3 ones.

3. Now subtract the tens column. Here 7 > 6 so we cannot subtract 7 from 6. Therefore regroup 5 hundred and 6 tens = 15 hundred and 16 tens. Subtract 16 – 7 = 9 tens.

4. Next subtract the hundreds column = 4 – 2 = 2 hundreds.

Question 12.

Answer:

590

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 0 – 0 = 0 ones.

3. Now subtract the tens column. Here 5 > 4 so we cannot subtract 5 from 4. Therefore regroup 6 hundred and 4 tens = 6 hundred and 14 tens. Subtract 14 – 5 = 9 tens.

4. Bring down the remaining number 5. The answer to this problem is 590.

Question 13.

Answer:

594

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 9 – 5 = 4 ones.

3. Now subtract the tens column. Here 3 > 2 so we cannot subtract 3 from 2. Therefore regroup 7 hundred and 2 tens = 7 hundred and 12 tens. Subtract 12 – 3 = 9 tens.

4. Next subtract the hundreds column 6 – 1 = 5 hundred.

Question 14.

Answer:

92

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 5 – 3 = 2 ones.

3. Now subtract the tens column. Here 3 > 2 so we cannot subtract 3 from 2. Therefore regroup 2 hundred and 2 tens = 2 hundred and 12 tens. Subtract 12 – 3 = 9 tens.

4. Next subtract the hundreds column = 1 – 1 = 0 hundreds.

Question 15.

Answer:

291

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 5 – 4 = 1 ones.

3. Now subtract the tens column. Here 9 > 8 so we cannot subtract 9 from 8. Therefore regroup 4 hundred and 8 tens = 4 hundred and 18 tens. Subtract 18 – 9 = 9 tens.

4. Next subtract the hundreds column = 3 – 1 = 2 hundreds.

Question 16.

Answer:

134

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 9 – 5 = 4 ones.

3. Now subtract the tens column. Here 9 > 5 so we cannot subtract 9 from 5. Therefore regroup 5 hundred and 2 tens = 5 hundred and 12 tens. Subtract 12 – 9 = 3 tens.

4. Next subtract the hundreds column = 4 – 3 = 1 hundred.

**Problem Solving**

Question 17.

Lucy went to basketball camp. 325-second graders and 234 first graders were there. How many more second graders were at camp?

_______________ more second graders

Answer:

91 more second graders.

Explanation:

Given,

There are 325-second graders.

In this, there are 234 graders

The difference between them is 325 – 234 = 91

Hence we need 91 more second graders at the camp.

Question 18.

417 boys were at the museum. 286 girls master were at the museum. How many more boys were at the museum than girls?

___________ more boys

Answer:

131 more boys

Explanation:

Given,

There are 417 boys at the museum.

There are 286 girls master were at the museum.

The difference between them is 417 – 286 = 131 more boys.

There are 131 more boys were at the museum than girls.

Question 19.

475 parents came to the school’s fall party. 294 parents had to leave early. How many parents are still at the fall party?

_____________ parents

Answer:

181 parents.

Explanation:

Given,

There 475 parents came to the school’s fall party.

There are 294 parents who had to leave early.

The difference between them is 475 – 294 = 181 parents.

Hence there are 181 parents are still at the fall party.

**Write Math** Explain how to regroup hundreds.

Answer:

### McGraw Hill My Math Grade 2 Chapter 7 Lesson 5 My Homework Answer Key

**Practice**

**Subtract.**

Question 1.

Answer:

91

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 2 – 1 = 2 ones.

3. Now subtract the tens column. Here 7 > 6 so we cannot subtract 7 from 6. Therefore regroup 3 hundred and 2 tens = 2 hundred and 16 tens. Subtract 16 – 7 = 9 tens.

4. Next subtract the hundreds column = 2 – 2 = 0 hundreds.

Question 2.

Answer:

291

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 2 – 1 = 1 ones.

3. Now subtract the tens column. Here 4> 3 so we cannot subtract 4 from 3. Therefore regroup 7 hundred and 3 tens = 6 hundred and 13 tens. Subtract 13 – 4 = 9 tens.

4. Next subtract the hundreds column = 6 – 4 = 2 hundreds.

Question 3.

Answer:

780

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 5 – 5 = 0 ones.

3. Now subtract the tens column. Here 5 > 3 so we cannot subtract 5 from 3. Therefore regroup 8 hundred and 13 tens = 7 hundred and 13 tens. Subtract 13 – 5 = 8 tens.

4. Now bring down the remaining number which is 8. Hence the answer to the given problem is 780.

Question 4.

Answer:

63

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 5 – 2 = 3 ones.

3. Now subtract the tens column. Here 7 > 3 so we cannot subtract 3 from 7. Therefore regroup 7 hundred and 3 tens = 7 hundred and 13 tens. Subtract 13 – 7 = 6 tens.

4. Next subtract the hundreds column = 2 – 2 = 0 hundreds.

Question 5.

Answer:

73

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 7 – 4 = 3 ones.

3. Now subtract the tens column. Here 4 > 1 so we cannot subtract 4 from 7. Therefore regroup 2 hundred and 1 tens = 1 hundred and 11 tens. Subtract 11 – 4 = 7 tens.

4. Next subtract the hundreds column = 1 – 1 = 0 hundreds.

Question 6.

Answer:

391

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 3 – 2 = 1 ones.

3. Now subtract the tens column. Here 6 > 5 so we cannot subtract 6 from 5. Therefore regroup 4 hundred and 5 tens = 3 hundred and 15 tens. Subtract 15 – 6 = 9 tens.

4. Now bring down the remaining 3 down. Hence the answer to the given problem is 391.

Question 7.

Answer:

590

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 1 – 1 = 0 ones.

3. Now subtract the tens column. Here 3 > 2 so we cannot subtract 3 from 2. Therefore regroup 7 hundred and 2 tens = 7 hundred and 12 tens. Subtract 12 – 3 = 9 tens.

4. Next subtract the hundreds column = 6 – 1 = 5 hundreds.

Question 8.

Answer:

293

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 5 – 2 = 3 ones.

3. Now subtract the tens column. Here 5 > 4 so we cannot subtract 5 from 4. Therefore regroup 7 hundred and 4 tens = 7 hundred and 14 tens. Subtract 14 – 5 = 9 tens.

4. Next subtract the hundreds column = 6 – 5 = 1 hundreds.

Question 9.

Answer:

83

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 5 – 2 = 3 ones.

3. Now subtract the tens column. Here 9 > 7 so we cannot subtract 9 from 7. Therefore regroup 3 hundred and 7 tens = 2 hundred and 17 tens. Subtract 17 – 9 = 8 tens.

4. Next subtract the hundreds column = 2 – 2 = 0 hundreds.

Question 10.

Answer:

141

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 3 – 2 = 1 ones.

3. Now subtract the tens column. Here 8 > 2 so we cannot subtract 8 from 2. Therefore regroup 4 hundred and 2 tens = 3 hundred and 12 tens. Subtract 12 – 8 = 4 tens.

4. Next subtract the hundreds column = 3 – 2 = 1 hundreds.

Question 11.

Answer:

191

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 4 – 3 = 1 ones.

3. Now subtract the tens column. Here 4 > 3 so we cannot subtract 4 from 3. Therefore regroup 4 hundred and 3 tens = 4 hundred and 13 tens. Subtract 13 – 4 = 9 tens.

4. Next subtract the hundreds column = 3 – 2 = 1 hundreds.

Question 12.

Answer:

163

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 5 – 2 = 3 ones.

3. Now subtract the tens column. Here 6 > 2 so we cannot subtract 6 from 2. Therefore regroup 6 hundred and 2 tens = 5 hundred and 12 tens. Subtract 12 – 6 = 6 tens.

4. Next subtract the hundreds column = 5 – 4 = 1 hundreds.

Question 13.

Answer:

94

Explanation:

1. Arrange the numbers vertically to solve the subtraction of three-digit numbers.

2. Subtract the one’s column. Subtract 8 – 4 = 4 ones.

3. Now subtract the tens column. Here 8 > 7 so we cannot subtract 8 from 7. Therefore regroup 2 hundred and 17 tens = 1 hundred and 17 tens. Subtract 17 – 8 = 9 tens.

4. Next subtract the hundreds column = 1 – 1 = 0 hundreds.

Question 14.

835 cows are in the field. 251 cows go in the barn. How many cows are still in the field?

_____________ cows

Answer:

584 cows

Explanation:

Given,

There are 835 cows are in the field.

There are 251 cows go in the barn.

The difference between them is 835 – 251 = 584 cows.

**Test Practice**

Question 15.

Which subtraction problem does not need regrouping to solve?

(A) 363 – 148

(B) 734 – 371

(C) 57 – 147

(D) 367 – 288

Answer:

57 – 147

Explanation:

The subtraction problem that does not need regrouping to solve is 57 – 147.

**Math at Home** Have your child explain when you need to regroup to solve a problem.

Answer:

If the digit in one place at the bottom of the given number is greater than the digit in the one’s place at the top then we have to regroup from the tens place to one’s place.