Cardinal Math

Addition with regrouping · sheet 4 of 30

Answer key

The answer, and what a wrong answer means.

The sheet
#ProblemAnswerIf they wrote…
1 46 + 15 61 51 forgets the ten511 writes the whole column sum
2 26 + 79 105 915 writes the whole column sum95 forgets the ten
3 35 + 17 52 412 writes the whole column sum42 forgets the ten
4 537 + 265 802 7912 writes the whole column sum792 forgets the ten892 carries two columns over
5 31 + 39 70 60 forgets the ten610 writes the whole column sum
6 495 + 314 809 1709 carries two columns over709 forgets the ten7109 writes the whole column sum
7 489 + 272 761 1751 carries two columns over61511 writes the whole column sum651 forgets the ten
8 685 + 198 883 1873 carries two columns over71713 writes the whole column sum773 forgets the ten
9 481 + 250 731 1631 carries two columns over6131 writes the whole column sum631 forgets the ten
10 259 + 337 596 5816 writes the whole column sum586 forgets the ten686 carries two columns over
11 583 + 343 926 1826 carries two columns over8126 writes the whole column sum826 forgets the ten
12 306 + 176 482 4712 writes the whole column sum472 forgets the ten572 carries two columns over
13 179 + 223 402 3912 writes the whole column sum392 forgets the ten492 carries two columns over
14 169 + 159 328 1318 carries two columns over21118 writes the whole column sum218 forgets the ten
15 35 + 59 94 814 writes the whole column sum84 forgets the ten
16 43 + 19 62 512 writes the whole column sum52 forgets the ten
17 559 + 148 707 6917 writes the whole column sum697 forgets the ten797 carries two columns over
18 46 + 16 62 512 writes the whole column sum52 forgets the ten
19 39 + 61 100 90 forgets the ten910 writes the whole column sum
20 209 + 418 627 6117 writes the whole column sum617 forgets the ten717 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.