Cardinal Math

Addition with regrouping · sheet 1 of 30

Answer key

The answer, and what a wrong answer means.

The sheet
#ProblemAnswerIf they wrote…
1 36 + 66 102 912 writes the whole column sum92 forgets the ten
2 12 + 39 51 41 forgets the ten411 writes the whole column sum
3 398 + 248 646 1636 carries two columns over51316 writes the whole column sum536 forgets the ten
4 579 + 225 804 7914 writes the whole column sum794 forgets the ten894 carries two columns over
5 21 + 19 40 30 forgets the ten310 writes the whole column sum
6 111 + 629 740 730 forgets the ten7310 writes the whole column sum830 carries two columns over
7 162 + 138 300 290 forgets the ten2910 writes the whole column sum390 carries two columns over
8 375 + 182 557 1457 carries two columns over4157 writes the whole column sum457 forgets the ten
9 26 + 67 93 813 writes the whole column sum83 forgets the ten
10 779 + 199 978 1968 carries two columns over81618 writes the whole column sum868 forgets the ten
11 119 + 587 706 6916 writes the whole column sum696 forgets the ten796 carries two columns over
12 220 + 391 611 1511 carries two columns over511 forgets the ten5111 writes the whole column sum
13 263 + 261 524 1424 carries two columns over4124 writes the whole column sum424 forgets the ten
14 236 + 238 474 4614 writes the whole column sum464 forgets the ten564 carries two columns over
15 27 + 38 65 515 writes the whole column sum55 forgets the ten
16 12 + 18 30 20 forgets the ten210 writes the whole column sum
17 418 + 109 527 5117 writes the whole column sum517 forgets the ten617 carries two columns over
18 61 + 39 100 90 forgets the ten910 writes the whole column sum
19 169 + 593 762 1752 carries two columns over61512 writes the whole column sum652 forgets the ten
20 25 + 38 63 513 writes the whole column sum53 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.