# Regrouping for Double-Digit Subtraction Two-Digit Subtraction – Regrouping.

## Presentation on theme: "Regrouping for Double-Digit Subtraction Two-Digit Subtraction – Regrouping."— Presentation transcript:

Regrouping for Double-Digit Subtraction Two-Digit Subtraction – Regrouping

Two approaches: Two-Digit Subtraction – Regrouping “10 First” Approach Common Approach

1. “10 First” Approach Two-Digit Subtraction – Regrouping 6 23 -16 23 -16

Start with subtracting the units column Two-Digit Subtraction – Regrouping 23 -16 23 -16 36363636

First, put 3 on Mathline Two-Digit Subtraction – Regrouping 23 -16 23 -16

Can we subtract six? Two-Digit Subtraction – Regrouping 23 -16 23 -16 6

6 No, 3 is less than 6 Two-Digit Subtraction – Regrouping So we need to regroup

23 -16 23 -16 6 10 First Approach! Two-Digit Subtraction – Regrouping

23 -16 23 -16 6 Start by clearing the MathLine Two-Digit Subtraction – Regrouping

23 -16 23 -16 6 Count 10 from right and move over Two-Digit Subtraction – Regrouping

23 -16 23 -16 6 This is regrouping Two-Digit Subtraction – Regrouping 11 One ten becomes ten ones

23 -16 23 -16 6 Now put the 3 ones back Two-Digit Subtraction – Regrouping 11

23 -16 23 -16 6 Now put the 3 ones back Two-Digit Subtraction – Regrouping 11 36363636

23 -16 23 -16 6 Two-Digit Subtraction – Regrouping 11 36363636 See 13

23 -16 23 -16 6 Now take 13 minus 6 Two-Digit Subtraction – Regrouping 11 36363636 123 45 6

23 -16 23 -16 6 See 7 Two-Digit Subtraction – Regrouping 11 36363636 7

Now we clear the MathLine to subtract the tens column Two-Digit Subtraction – Regrouping 23 -16 23 -16 1 7 1

Count ten rings on MathLine Two-Digit Subtraction – Regrouping 23 -16 23 -16 7 11 7

Two-Digit Subtraction – Regrouping 23 -16 23 -16 7 11 7 Then subtract 10 Count ten rings on MathLine

Two-Digit Subtraction – Regrouping 23 -16 23 -16 7 11 7 See zero on MathLine 0

2. Common Approach Two-Digit Subtraction – Regrouping 6 23 -16 23 -16

Start with subtracting the units column Two-Digit Subtraction – Regrouping 23 -16 23 -16 36363636

First, put 3 on Mathline Two-Digit Subtraction – Regrouping 23 -16 23 -16

Can we subtract six? Two-Digit Subtraction – Regrouping 23 -16 23 -16 6

6 No, 3 is less than 6 Two-Digit Subtraction – Regrouping So we need to regroup

23 -16 23 -16 6 Common Approach! Two-Digit Subtraction – Regrouping

23 -16 23 -16 Count 10 rings from the right side to regroup. Two-Digit Subtraction – Regrouping 1

23 -16 23 -16 Two-Digit Subtraction – Regrouping 12 Count 10 rings from the right side to regroup.

23 -16 23 -16 Two-Digit Subtraction – Regrouping Count 10 rings from the right side to regroup. 123

23 -16 23 -16 Two-Digit Subtraction – Regrouping Count 10 rings from the right side to regroup. 231 4

23 -16 23 -16 Two-Digit Subtraction – Regrouping Count 10 rings from the right side to regroup. 23145

23 -16 23 -16 Two-Digit Subtraction – Regrouping Count 10 rings from the right side to regroup. 231456

23 -16 23 -16 Two-Digit Subtraction – Regrouping Count 10 rings from the right side to regroup. 2314567

23 -16 23 -16 Two-Digit Subtraction – Regrouping Count 10 rings from the right side to regroup. 23145678

23 -16 23 -16 Two-Digit Subtraction – Regrouping Count 10 rings from the right side to regroup. 231456789

23 -16 23 -16 Two-Digit Subtraction – Regrouping Count 10 rings from the right side to regroup. 23145678910

23 -16 23 -16 6 Explain this ten came from the tens column 11 Two-Digit Subtraction – Regrouping Move rings to the left. This is regrouping! 23 -16 23 -16

Two-Digit Subtraction – Regrouping 23-16 23-16 23-16 23-16 11 Next, subtract 13 minus 6 123 45 6 1

Two-Digit Subtraction – Regrouping 23 -16 23 -16 11 See 7 in the ones column 7 1

Now we clear the MathLine to subtract the tens column Two-Digit Subtraction – Regrouping 23 -16 23 -16 1 7 1

Count ten rings on MathLine Two-Digit Subtraction – Regrouping 23 -16 23 -16 7 11 7

Two-Digit Subtraction – Regrouping 23 -16 23 -16 7 11 7 Then subtract 10 Count ten rings on MathLine

Two-Digit Subtraction – Regrouping 23 -16 23 -16 7 11 7 See zero on MathLine 0