Cardinal Math

Addition with regrouping · sheet 10 of 30

Answer key

The answer, and what a wrong answer means.

The sheet
#ProblemAnswerIf they wrote…
1 22 + 38 60 50 forgets the ten510 writes the whole column sum
2 399 + 255 654 1644 carries two columns over51414 writes the whole column sum544 forgets the ten
3 31 + 69 100 90 forgets the ten910 writes the whole column sum
4 291 + 180 471 1371 carries two columns over3171 writes the whole column sum371 forgets the ten
5 585 + 316 901 891 forgets the ten8911 writes the whole column sum991 carries two columns over
6 15 + 35 50 40 forgets the ten410 writes the whole column sum
7 469 + 240 709 1609 carries two columns over609 forgets the ten6109 writes the whole column sum
8 38 + 26 64 514 writes the whole column sum54 forgets the ten
9 795 + 199 994 1984 carries two columns over81814 writes the whole column sum884 forgets the ten
10 591 + 197 788 1688 carries two columns over6188 writes the whole column sum688 forgets the ten
11 239 + 209 448 4318 writes the whole column sum438 forgets the ten538 carries two columns over
12 43 + 29 72 612 writes the whole column sum62 forgets the ten
13 339 + 538 877 8617 writes the whole column sum867 forgets the ten967 carries two columns over
14 29 + 25 54 414 writes the whole column sum44 forgets the ten
15 88 + 13 101 91 forgets the ten911 writes the whole column sum
16 11 + 39 50 40 forgets the ten410 writes the whole column sum
17 498 + 203 701 691 forgets the ten6911 writes the whole column sum791 carries two columns over
18 689 + 115 804 7914 writes the whole column sum794 forgets the ten894 carries two columns over
19 127 + 608 735 7215 writes the whole column sum725 forgets the ten825 carries two columns over
20 377 + 376 753 1743 carries two columns over61413 writes the whole column sum643 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.