Cardinal Math

Addition with regrouping · sheet 20 of 30

Answer key

The answer, and what a wrong answer means.

The sheet
#ProblemAnswerIf they wrote…
1 25 + 17 42 312 writes the whole column sum32 forgets the ten
2 189 + 262 451 1441 carries two columns over31411 writes the whole column sum341 forgets the ten
3 69 + 14 83 713 writes the whole column sum73 forgets the ten
4 199 + 197 396 1386 carries two columns over21816 writes the whole column sum286 forgets the ten
5 61 + 39 100 90 forgets the ten910 writes the whole column sum
6 129 + 278 407 3917 writes the whole column sum397 forgets the ten497 carries two columns over
7 492 + 270 762 1662 carries two columns over6162 writes the whole column sum662 forgets the ten
8 155 + 148 303 2913 writes the whole column sum293 forgets the ten393 carries two columns over
9 55 + 28 83 713 writes the whole column sum73 forgets the ten
10 23 + 48 71 61 forgets the ten611 writes the whole column sum
11 19 + 11 30 20 forgets the ten210 writes the whole column sum
12 184 + 179 363 1353 carries two columns over21513 writes the whole column sum253 forgets the ten
13 77 + 25 102 912 writes the whole column sum92 forgets the ten
14 281 + 690 971 1871 carries two columns over8171 writes the whole column sum871 forgets the ten
15 428 + 377 805 7915 writes the whole column sum795 forgets the ten895 carries two columns over
16 165 + 115 280 270 forgets the ten2710 writes the whole column sum370 carries two columns over
17 259 + 132 391 381 forgets the ten3811 writes the whole column sum481 carries two columns over
18 609 + 179 788 7718 writes the whole column sum778 forgets the ten878 carries two columns over
19 44 + 27 71 61 forgets the ten611 writes the whole column sum
20 274 + 682 956 1856 carries two columns over8156 writes the whole column sum856 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.