ONE-APART FACTS (Near Doubles) New to grade 2 Double the smaller number and add 1. Students need to be convinced that the larger number can be partitioned without changing the sum. For example, they need to see that for 4 + 5, the 5 can be partitioned into 4 and 1, and that the 4 can be combined with the other 4 before adding the 1. You could have students create Unifix Cube towers for numbers 2 to 9, have them take two consecutive number towers, and take one cube off the larger tower so they can see the double towers and the 1. In symbols: 4 + 5 = 4 + (4 + 1) (4 + 4) + 1 = 8 + 1 = 9. Examples: For 2 + 3, think: 2 and 2 is 4, and plus 1 is 5. For 8 + 7, think: 7 and 7 is 14 , and plus 1 is 15.

One-Apart (Near Doubles) From Grade 2 Curriculum Document There are 14 near-doubles facts: 2 + 3, 3 + 4, 4 + 5, 5 + 6, 6 + 7, 7 + 8, 8 + 9 and their commutative pairs 3 + 2, 4 + 3, 5 + 4, 6 + 5, 7 + 6, 8 + 7, 9 + 8. (Note: 1 + 2 and 2 + 1 were already included in the plus-one facts but could also be thought of as 1-aparts.) And the related subtraction facts 5 – 2, 5 – 3, 7 – 4, 7 – 3, 9 – 5, 9 – 4, 11 – 6, 11 – 5, 13 – 7, 13 – 6, 15 – 8, 15 – 7, 17 – 9, 17 – 8. This strategy is a combination of the doubles facts and the plus-one facts. It involves doubling the smaller number and adding one. (Some students may double the larger and subtract 1.) Students need to be convinced that the larger number can be partitioned without changing the sum. For example, they need to see that for 4 + 5, the 5 can be partitioned into 4 and 1, and that the 4 can be combined with the other 4 before adding the 1. For example, for 2 + 3, think, double 2 is 4 and the next number is 5; or 2 and 2 is 4, and plus 1 is 5.   For subtraction the think addition strategy would be a starting point. For example for the fact 13 – 6, students would double the minuend 6, get 12 and see that 1 more is needed to make the 13, so 13 – 6 is 7. 13 – 7. Think double 7 is 14, I have one too many so 13 – 7 is 6.

5+6

8+9

7+6

3+4

6+7

8+7

5+4

4+5

7+8

3+2

4+3

9+8

6+5

2+3

5-2

5-3

7-4

7-3

9-5

9-4

11-6

11-5

13-7

13-6

15-8

15-7

17-9

17-8