operations · Foundation · AC9MFN05
Subtraction within ten
Subtraction can mean taking some away. Start with the whole group, remove the amount in the question, then count what is left. Without a picture, count back: from 8, take away 3 by saying 7, 6, 5. When the missing number is the start, put back what was taken away.
Sample questions
3 − 1 = ?
- Start with 3 counters. 1 is crossed out.
- Count the counters that are left: 1, 2.
- 3 − 1 = 2.
Answer: 2
5 − 1 = ?
- Start with 5 counters. 1 is crossed out.
- Count the counters that are left: 1, 2, 3, 4.
- 5 − 1 = 4.
Answer: 4
2 − 1 = ?
- Start with 2 counters. 1 is crossed out.
- Count the counters that are left: 1.
- 2 − 1 = 1.
Answer: 1