Cardinal Math

Addition with regrouping · sheet 5 of 30

Answer key

The answer, and what a wrong answer means.

The sheet
#ProblemAnswerIf they wrote…
1 87 + 17 104 914 writes the whole column sum94 forgets the ten
2 15 + 58 73 613 writes the whole column sum63 forgets the ten
3 405 + 207 612 6012 writes the whole column sum602 forgets the ten702 carries two columns over
4 369 + 119 488 4718 writes the whole column sum478 forgets the ten578 carries two columns over
5 227 + 106 333 3213 writes the whole column sum323 forgets the ten423 carries two columns over
6 395 + 157 552 1542 carries two columns over41412 writes the whole column sum442 forgets the ten
7 763 + 174 937 1837 carries two columns over8137 writes the whole column sum837 forgets the ten
8 34 + 58 92 812 writes the whole column sum82 forgets the ten
9 575 + 128 703 6913 writes the whole column sum693 forgets the ten793 carries two columns over
10 22 + 29 51 41 forgets the ten411 writes the whole column sum
11 498 + 249 747 1737 carries two columns over61317 writes the whole column sum637 forgets the ten
12 330 + 280 610 1510 carries two columns over510 forgets the ten5110 writes the whole column sum
13 275 + 127 402 3912 writes the whole column sum392 forgets the ten492 carries two columns over
14 17 + 56 73 613 writes the whole column sum63 forgets the ten
15 42 + 58 100 90 forgets the ten910 writes the whole column sum
16 177 + 129 306 2916 writes the whole column sum296 forgets the ten396 carries two columns over
17 366 + 160 526 1426 carries two columns over4126 writes the whole column sum426 forgets the ten
18 14 + 29 43 313 writes the whole column sum33 forgets the ten
19 199 + 761 960 1950 carries two columns over81510 writes the whole column sum850 forgets the ten
20 57 + 24 81 71 forgets the ten711 writes the whole column sum

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.