Cardinal Math

Addition with regrouping · sheet 19 of 30

Answer key

The answer, and what a wrong answer means.

The sheet
#ProblemAnswerIf they wrote…
1 399 + 106 505 4915 writes the whole column sum495 forgets the ten595 carries two columns over
2 213 + 289 502 4912 writes the whole column sum492 forgets the ten592 carries two columns over
3 565 + 256 821 1811 carries two columns over711 forgets the ten71111 writes the whole column sum
4 18 + 55 73 613 writes the whole column sum63 forgets the ten
5 209 + 767 976 66 carries two columns over9616 writes the whole column sum966 forgets the ten
6 86 + 14 100 90 forgets the ten910 writes the whole column sum
7 158 + 186 344 1334 carries two columns over21314 writes the whole column sum234 forgets the ten
8 792 + 123 915 1815 carries two columns over8115 writes the whole column sum815 forgets the ten
9 19 + 17 36 216 writes the whole column sum26 forgets the ten
10 29 + 21 50 40 forgets the ten410 writes the whole column sum
11 199 + 199 398 1388 carries two columns over21818 writes the whole column sum288 forgets the ten
12 28 + 28 56 416 writes the whole column sum46 forgets the ten
13 290 + 190 480 1380 carries two columns over3180 writes the whole column sum380 forgets the ten
14 107 + 889 996 86 carries two columns over9816 writes the whole column sum986 forgets the ten
15 89 + 18 107 917 writes the whole column sum97 forgets the ten
16 190 + 491 681 1581 carries two columns over5181 writes the whole column sum581 forgets the ten
17 45 + 48 93 813 writes the whole column sum83 forgets the ten
18 308 + 129 437 4217 writes the whole column sum427 forgets the ten527 carries two columns over
19 147 + 659 806 7916 writes the whole column sum796 forgets the ten896 carries two columns over
20 31 + 39 70 60 forgets the ten610 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.