Cardinal Math

Addition with regrouping · sheet 17 of 30

Answer key

The answer, and what a wrong answer means.

The sheet
#ProblemAnswerIf they wrote…
1 586 + 336 922 1912 carries two columns over81112 writes the whole column sum812 forgets the ten
2 13 + 89 102 912 writes the whole column sum92 forgets the ten
3 279 + 547 826 1816 carries two columns over71116 writes the whole column sum716 forgets the ten
4 51 + 19 70 60 forgets the ten610 writes the whole column sum
5 190 + 490 680 1580 carries two columns over5180 writes the whole column sum580 forgets the ten
6 107 + 349 456 4416 writes the whole column sum446 forgets the ten546 carries two columns over
7 302 + 299 601 591 forgets the ten5911 writes the whole column sum691 carries two columns over
8 22 + 19 41 31 forgets the ten311 writes the whole column sum
9 227 + 566 793 7813 writes the whole column sum783 forgets the ten883 carries two columns over
10 338 + 566 904 8914 writes the whole column sum894 forgets the ten994 carries two columns over
11 15 + 47 62 512 writes the whole column sum52 forgets the ten
12 509 + 197 706 6916 writes the whole column sum696 forgets the ten796 carries two columns over
13 12 + 39 51 41 forgets the ten411 writes the whole column sum
14 254 + 271 525 1425 carries two columns over4125 writes the whole column sum425 forgets the ten
15 597 + 229 826 1816 carries two columns over71116 writes the whole column sum716 forgets the ten
16 249 + 109 358 3418 writes the whole column sum348 forgets the ten448 carries two columns over
17 43 + 27 70 60 forgets the ten610 writes the whole column sum
18 33 + 48 81 71 forgets the ten711 writes the whole column sum
19 78 + 24 102 912 writes the whole column sum92 forgets the ten
20 283 + 156 439 1339 carries two columns over3139 writes the whole column sum339 forgets the ten

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 in the guide. Problems marked "no pattern to catch" are the plain ones; a child who gets only those right is telling you something too.

Writes the whole column sum 20 of 20 problems

Writes each column's full total into the answer: 8 and 5 are 13, so 13 goes down; 3 and 4 are 7.

38 + 45 they write 713 it is 83

Forgets the ten 20 of 20 problems

Adds each column and keeps only the ones digit of the total. The ten that should move left gets dropped.

38 + 45 they write 73 it is 83

Carries two columns over 12 of 20 problems

The carried ten skips a column and lands two places left, where it's worth a hundred.

375 + 182 they write 1457 it is 557

Not sure which? The five-minute check picks the problems that tell the patterns apart and names the one it sees.