Represent Regrouping
Add Two-Digit Numbers
Subtract Two-Digit Numbers
100

How many ones make a ten?

10 

100

14+15=

29

100
25-13=

12

200

When do we regroup in addition?

When there are 10 or more ones. 

200

23+25= 

48

200

34-21=

13

300

When do we regroup in subtraction?

When there are not enough ones to subtract/when the top digit in the ones place is smaller than the bottom digit. 

300

37+46=

83

300

44-27=

17

400

What is the first step when adding two-digit numbers? 

Add the digits in the ones place. 

400

45+45=

90

400

73-48=

25

500

How can I check to see if the difference in my subtraction problem is correct? 

Add the difference with the number you are subtracting. Example (37-19=18) -> 18+19=37

500

52+49

101
500

94-75=

19