1. Two approaches for Subtraction Regrouping Two-Digit Subtraction – Regrouping

2. 1. Common Approach Two-Digit Subtraction – Regrouping

3. First, put 3 on MathLine 23-16 23-16 23-16 23-16 Two-Digit Subtraction – Regrouping Step 1

4. Can’t subtract 6 from 3! 23-16 23-16 23-16 23-16 Two-Digit Subtraction – Regrouping Step 1

5. Regroup one 10 into 10 ones by counting 10 rings from the reserve of rings. Two-Digit Subtraction – Regrouping Step 2 12345678910

6. Explain that this ten came from the tens column, and we are regrouping (or borrowing) to the ones column. Two-Digit Subtraction – Regrouping Step 2 23 -16 23 -16

7. Slide rings to the left. 2 -16 23 -16 11 Two-Digit Subtraction – Regrouping Step 3 3 See 13 in the ones column.

8. Subtract 6 from 13 23-16 23-16 23-16 23-16 11 Two-Digit Subtraction – Regrouping Step 4

9. See 7 in the units column. 23 -16 23 -16 7 11 Two-Digit Subtraction – Regrouping Step 5 7

10. Now we clear the MathLine to subtract the tens column Two-Digit Subtraction – Regrouping Step 6

11. Count out ten rings on MathLine. Two-Digit Subtraction – Regrouping Step 6 23 -16 23 -16 7 11 7

12. Then subtract 10 from 10 on MathLine Two-Digit Subtraction – Regrouping Step 6 23 -_6 23 -_6 7 11 7 1

13. See zero on MathLine Two-Digit Subtraction – Regrouping Step 6 23 -16 23 -16 7 11 70

14. “Ten First” Approach 23 -16 23 -16 Two-Digit Subtraction – Regrouping Step 1

15. 23 -16 23 -16 Two-Digit Subtraction – Regrouping Step 1 First, put 3 on MathLine

16. Can’t subtract 6 from 3! 23-16 23-16 23-16 23-16 Two-Digit Subtraction – Regrouping Step 2

17. So we clear the MathLine Two-Digit Subtraction – Regrouping Step 2 Explain that first we regroup (or borrow) ten from the tens column

18. Regroup one ten into ten ones, Put 10 on MathLine. 23 -16 23 -16 1 Two-Digit Subtraction – Regrouping Step 3 1

19. Then put the 3 ones back… 2 -16 23 -16 Two-Digit Subtraction – Regrouping Step 3 11 123 …from the ones column 3

20. See 13 on MathLine. 2 -16 23 -16 Two-Digit Subtraction – Regrouping Step 3 11 3

21. Take 13 minus 6. 23-16 23-16 23-16 23-16 11 Two-Digit Subtraction – Regrouping Step 4 654321

22. Now subtract six rings. 23 -16 23 -16 11 Two-Digit Subtraction – Regrouping Step 4

23. See 7 in ones column. 23 -16 23 -16 7 11 Two-Digit Subtraction – Regrouping Step 5 13 – 6 = 7 7

24. Now we clear the MathLine to subtract the tens column Two-Digit Subtraction – Regrouping Step 6

25. Count out ten rings on MathLine 23 -16 23 -16 7 11 Two-Digit Subtraction – Regrouping Step 6

26. 23 -16 23 -16 7 11 Two-Digit Subtraction – Regrouping Step 6 Then subtract 10 from 10 on MathLine 0

27. 23 -16 23 -16 7 11 Two-Digit Subtraction – Regrouping Step 6 Then subtract 10 from 10 on MathLine 0

28. 23 -16 23 -16 7 11 Two-Digit Subtraction – Regrouping Step 6 So 23 – 16 = 7