Compose, Decompose & Regroup 3-Digit Numbers – Math Worksheet for 8-Year-Olds (Grade 3)

Instructions

Let's explore 3-digit numbers! In this worksheet, you'll practice putting numbers together, taking them apart, and showing them in new ways. Have fun being a number expert!

Part 1: Number Builders

Use the clues to build the 3-digit number. Write the final number on the line.

1. 400 + 20 + 7 = __________

2. 800 + 90 + 1 = __________

3. 5 hundreds + 3 tens + 6 ones = __________

4. 200 + 0 + 4 = __________

5. 7 hundreds + 5 tens + 0 ones = __________

Part 2: Number Detectives

Break the number down into its hundreds, tens, and ones parts (expanded form).

1. 682 = __________ + __________ + __________

2. 159 = __________ + __________ + __________

3. 903 = __________ + __________ + __________

Now, find the value of the underlined digit.

4. In 375, the value of the 7 is __________.

5. In 841, the value of the 8 is __________.

Part 3: Super Shifters

Numbers can be written in different ways by regrouping. Fill in the missing number to make the sentences true.

Example: The number is 352. Another way to write it is: 2 hundreds + 15 tens + 2 ones.

1. The number is 463. Another way to write it is:
   3 hundreds + __________ tens + 3 ones.

2. The number is 285. Another way to write it is:
   2 hundreds + 7 tens + __________ ones.

3. The number is 718. Another way to write it is:
   __________ hundreds + 11 tens + 8 ones.

4. The number is 530. Another way to write it is:
   4 hundreds + __________ tens + 0 ones.

Answer Key

Part 1: Number Builders

1. 427
2. 891
3. 536
4. 204
5. 750

Part 2: Number Detectives

1. 600 + 80 + 2
2. 100 + 50 + 9
3. 900 + 0 + 3
4. 70
5. 800

Part 3: Super Shifters

1. 16
2. 15
3. 6
4. 13