Cardinal Math

Addition with regrouping · sheet 23 of 30

Answer key

The answer, and what a wrong answer means.

The sheet
#ProblemAnswerIf they wrote…
1 128 + 558 686 6716 writes the whole column sum676 forgets the ten776 carries two columns over
2 409 + 119 528 5118 writes the whole column sum518 forgets the ten618 carries two columns over
3 764 + 116 880 870 forgets the ten8710 writes the whole column sum970 carries two columns over
4 388 + 474 862 1852 carries two columns over71512 writes the whole column sum752 forgets the ten
5 12 + 18 30 20 forgets the ten210 writes the whole column sum
6 364 + 366 730 1720 carries two columns over61210 writes the whole column sum620 forgets the ten
7 57 + 43 100 90 forgets the ten910 writes the whole column sum
8 187 + 179 366 1356 carries two columns over21516 writes the whole column sum256 forgets the ten
9 379 + 129 508 4918 writes the whole column sum498 forgets the ten598 carries two columns over
10 13 + 77 90 80 forgets the ten810 writes the whole column sum
11 77 + 29 106 916 writes the whole column sum96 forgets the ten
12 11 + 29 40 30 forgets the ten310 writes the whole column sum
13 353 + 491 844 1744 carries two columns over7144 writes the whole column sum744 forgets the ten
14 386 + 370 756 1656 carries two columns over6156 writes the whole column sum656 forgets the ten
15 59 + 18 77 617 writes the whole column sum67 forgets the ten
16 391 + 144 535 1435 carries two columns over4135 writes the whole column sum435 forgets the ten
17 22 + 59 81 71 forgets the ten711 writes the whole column sum
18 39 + 14 53 413 writes the whole column sum43 forgets the ten
19 155 + 249 404 3914 writes the whole column sum394 forgets the ten494 carries two columns over
20 129 + 478 607 5917 writes the whole column sum597 forgets the ten697 carries two columns over

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.