Cardinal Math

Addition with regrouping · sheet 26 of 30

Answer key

The answer, and what a wrong answer means.

The sheet
#ProblemAnswerIf they wrote…
1 39 + 33 72 612 writes the whole column sum62 forgets the ten
2 64 + 39 103 913 writes the whole column sum93 forgets the ten
3 124 + 779 903 8913 writes the whole column sum893 forgets the ten993 carries two columns over
4 129 + 574 703 6913 writes the whole column sum693 forgets the ten793 carries two columns over
5 381 + 275 656 1556 carries two columns over5156 writes the whole column sum556 forgets the ten
6 14 + 29 43 313 writes the whole column sum33 forgets the ten
7 463 + 343 806 1706 carries two columns over706 forgets the ten7106 writes the whole column sum
8 177 + 458 635 1625 carries two columns over51215 writes the whole column sum525 forgets the ten
9 15 + 15 30 20 forgets the ten210 writes the whole column sum
10 117 + 836 953 43 carries two columns over9413 writes the whole column sum943 forgets the ten
11 29 + 35 64 514 writes the whole column sum54 forgets the ten
12 269 + 138 407 3917 writes the whole column sum397 forgets the ten497 carries two columns over
13 244 + 119 363 3513 writes the whole column sum353 forgets the ten453 carries two columns over
14 72 + 28 100 90 forgets the ten910 writes the whole column sum
15 153 + 150 303 1203 carries two columns over203 forgets the ten2103 writes the whole column sum
16 368 + 576 944 1934 carries two columns over81314 writes the whole column sum834 forgets the ten
17 498 + 288 786 1776 carries two columns over61716 writes the whole column sum676 forgets the ten
18 23 + 27 50 40 forgets the ten410 writes the whole column sum
19 19 + 76 95 815 writes the whole column sum85 forgets the ten
20 808 + 114 922 12 carries two columns over9112 writes the whole column sum912 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.