Missing Addend

Missing Addend

A missing addend is one number in an addition when you know the total and the other addend. To find it, use the fact that addition and subtraction are inverse operations.

Method

1. Read the equation carefully. Identify the known addend and the total.
2. Subtract the known addend from the total.
   • Missing addend = total − known addend
3. Write the answer clearly as the number that makes the addition true.

Why this works

If one part and the whole are known, subtraction tells you how much is left. That leftover amount is the missing addend.

Check your work

Add your answer to the known addend. If the result equals the total, your answer is correct.

Example idea

If the total is 9 and one addend is 4, the missing addend is 9 − 4 = 5. Check: 4 + 5 = 9.

Tip

If the numbers are shown with objects, count the known group first, then count how many more are needed to reach the total.