Cardinal Math

Addition with regrouping · sheet 27 of 30

Answer key

The answer, and what a wrong answer means.

The sheet
#ProblemAnswerIf they wrote…
1 69 + 36 105 915 writes the whole column sum95 forgets the ten
2 21 + 49 70 60 forgets the ten610 writes the whole column sum
3 190 + 373 563 1463 carries two columns over4163 writes the whole column sum463 forgets the ten
4 108 + 305 413 4013 writes the whole column sum403 forgets the ten503 carries two columns over
5 18 + 17 35 215 writes the whole column sum25 forgets the ten
6 44 + 48 92 812 writes the whole column sum82 forgets the ten
7 249 + 448 697 6817 writes the whole column sum687 forgets the ten787 carries two columns over
8 578 + 198 776 1766 carries two columns over61616 writes the whole column sum666 forgets the ten
9 13 + 58 71 61 forgets the ten611 writes the whole column sum
10 27 + 65 92 812 writes the whole column sum82 forgets the ten
11 289 + 115 404 3914 writes the whole column sum394 forgets the ten494 carries two columns over
12 348 + 396 744 1734 carries two columns over61314 writes the whole column sum634 forgets the ten
13 127 + 273 400 390 forgets the ten3910 writes the whole column sum490 carries two columns over
14 259 + 109 368 3518 writes the whole column sum358 forgets the ten458 carries two columns over
15 436 + 464 900 890 forgets the ten8910 writes the whole column sum990 carries two columns over
16 21 + 19 40 30 forgets the ten310 writes the whole column sum
17 272 + 144 416 1316 carries two columns over3116 writes the whole column sum316 forgets the ten
18 282 + 590 872 1772 carries two columns over7172 writes the whole column sum772 forgets the ten
19 32 + 69 101 91 forgets the ten911 writes the whole column sum
20 197 + 349 546 1536 carries two columns over41316 writes the whole column sum436 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.