Answer key

The answer, and what a wrong answer means.

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