Skill: 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 $83-78$.

1. Start at $78$.
2. Count forward to $83$ without counting $78$ 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
3. 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 $83$.