Use counting on to subtract

Counting on interprets subtraction as finding the unknown amount that must be added to the subtrahend to reach the minuend: for $83-78$ , count forward from 78 to 83, and the number of steps is 5. A number line or related addition equation makes the inverse relationship explicit and helps avoid counting the starting number as a step; the focus is on whole numbers within 100, not generalized multi-digit or fractional subtraction.

Detailed Explanation: Use counting on to subtract

To subtract using counting on, start with the smaller number and count forward until you reach the larger number. The number of steps you count is the difference.

Example: Find $83-78$ .

Start at $78$ .
Count forward to $83$ $83$ without counting $78$ $78$ as a step:
- $78$ to $79$ : 1 step
- $79$ to $80$ : 2 steps
- $80$ to $81$ : 3 steps
- $81$ to $82$ : 4 steps
- $82$ to $83$ : 5 steps
You counted $5$ steps, so:

83-78=5

You can check with addition:

78+5=83

So, $5$ is the amount you add to $78$ to reach $83$ .

Learn by doing: Use counting on to subtract

Click a topic below to practice the foundational skills you'll need, learn the steps, or master this skill

Practice with unlimited practice problems

Subtraction - Missing Value, 2 Digit, 1 Number

Earned ?

Use counting on to subtract

Detailed Explanation: Use counting on to subtract

Learn by doing: Use counting on to subtract

Practice with unlimited practice problems

Practice:

Subtraction - Missing Value, 2 Digit, 1 Number