Cardinal Math

Addition with regrouping · sheet 13 of 30

Answer key

The answer, and what a wrong answer means.

The sheet
#ProblemAnswerIf they wrote…
1 18 + 16 34 214 writes the whole column sum24 forgets the ten
2 29 + 13 42 312 writes the whole column sum32 forgets the ten
3 35 + 68 103 913 writes the whole column sum93 forgets the ten
4 706 + 198 904 8914 writes the whole column sum894 forgets the ten994 carries two columns over
5 233 + 268 501 491 forgets the ten4911 writes the whole column sum591 carries two columns over
6 360 + 370 730 1630 carries two columns over6130 writes the whole column sum630 forgets the ten
7 33 + 57 90 80 forgets the ten810 writes the whole column sum
8 174 + 188 362 1352 carries two columns over21512 writes the whole column sum252 forgets the ten
9 805 + 127 932 22 carries two columns over9212 writes the whole column sum922 forgets the ten
10 549 + 189 738 1728 carries two columns over61218 writes the whole column sum628 forgets the ten
11 127 + 848 975 65 carries two columns over9615 writes the whole column sum965 forgets the ten
12 16 + 35 51 41 forgets the ten411 writes the whole column sum
13 492 + 165 657 1557 carries two columns over5157 writes the whole column sum557 forgets the ten
14 246 + 109 355 3415 writes the whole column sum345 forgets the ten445 carries two columns over
15 171 + 196 367 1267 carries two columns over2167 writes the whole column sum267 forgets the ten
16 77 + 23 100 90 forgets the ten910 writes the whole column sum
17 159 + 366 525 1515 carries two columns over41115 writes the whole column sum415 forgets the ten
18 55 + 16 71 61 forgets the ten611 writes the whole column sum
19 407 + 393 800 790 forgets the ten7910 writes the whole column sum890 carries two columns over
20 42 + 29 71 61 forgets the ten611 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.