Answer key

The answer, and what a wrong answer means.

#	Problem	Answer	If they wrote…
1	6 + 7	13	no pattern to catch here
2	6 + 5	11	no pattern to catch here
3	3 + 2	5	no pattern to catch here
4	8 + 8	16	no pattern to catch here
5	9 + 1	10	no pattern to catch here
6	9 + 2	11	12 rounding to add, then forgetting to adjust
7	9 + 9	18	no pattern to catch here
8	4 + 4	8	no pattern to catch here
9	8 + 3	11	13 rounding to add, then forgetting to adjust
10	3 + 7	10	no pattern to catch here
11	9 + 7	16	17 rounding to add, then forgetting to adjust
12	8 + 7	15	no pattern to catch here
13	8 + 8	16	18 rounding to add, then forgetting to adjust
14	9 + 8	17	18 rounding to add, then forgetting to adjust
15	7 + 4	11	no pattern to catch here
16	6 + 6	12	no pattern to catch here
17	9 + 8	17	18 rounding to add, then forgetting to adjust
18	8 + 4	12	14 rounding to add, then forgetting to adjust
19	8 + 9	17	no pattern to catch here
20	3 + 4	7	no pattern to catch here

Reading the wrong answers

One wrong answer is a slip. The same pattern on three or more problems is a rule your child is following, and it has a name and a fix. Problems marked "no pattern to catch" are the plain ones; a child who gets only those right is telling you something too.

Reading the wrong answers

Rounding to add, then forgetting to adjust 7 of 20 problems