1/15
00:00

F.2 Add using expanded form: up to three digits

Loading questions...

What is expanded form?

Expanded form is a way to write numbers by showing the value of each digit. It helps us understand how much each digit is worth in a number.

Examples:
  • 347 = 300 + 40 + 7
  • 526 = 500 + 20 + 6
  • 189 = 100 + 80 + 9
Note

Think of expanded form as "stretching out" a number to see all its parts. The hundreds, tens, and ones are separated by plus signs.

How to write numbers in expanded form

To write a number in expanded form, identify the value of each digit based on its place (hundreds, tens, or ones).

Steps:
  • Look at the hundreds digit: multiply by 100
  • Look at the tens digit: multiply by 10
  • Look at the ones digit: keep as is
  • Write them with plus signs between
Note

Always check: does your expanded form add up to the original number?

Adding with one number expanded

When adding with one number expanded, we break apart one number into its place values while keeping the other number whole.

Example: 247 + 138
  • Expand 247: 200 + 40 + 7
  • Add to 138: 200 + 40 + 7 + 138
  • Add hundreds: 200 + 100 = 300
  • Add tens: 40 + 30 = 70
  • Add ones: 7 + 8 = 15
  • Combine: 300 + 70 + 15 = 385
Note

This method helps when one number is easier to break apart than the other.

Adding with both numbers expanded

When adding with both numbers expanded, we break apart both numbers into their place values before adding.

Example: 362 + 475
  • Expand 362: 300 + 60 + 2
  • Expand 475: 400 + 70 + 5
  • Add hundreds: 300 + 400 = 700
  • Add tens: 60 + 70 = 130
  • Add ones: 2 + 5 = 7
  • Combine: 700 + 130 + 7 = 837
Note

This method is helpful when both numbers have many digits or when regrouping is needed.

When to use expanded form addition

Expanded form addition is especially useful when numbers are large or when regrouping is needed in the calculation.

Examples:
  • Use with numbers that have many digits
  • Use when you need to regroup (carry over)
  • Use to check your work with standard addition
Note

If you get stuck with standard addition, try expanded form to see the problem in a different way.