Cardinal Math

Addition with regrouping · sheet 11 of 30

Answer key

The answer, and what a wrong answer means.

The sheet
#ProblemAnswerIf they wrote…
1 54 + 46 100 90 forgets the ten910 writes the whole column sum
2 143 + 359 502 4912 writes the whole column sum492 forgets the ten592 carries two columns over
3 38 + 42 80 70 forgets the ten710 writes the whole column sum
4 679 + 198 877 1867 carries two columns over71617 writes the whole column sum767 forgets the ten
5 17 + 87 104 914 writes the whole column sum94 forgets the ten
6 230 + 591 821 1721 carries two columns over7121 writes the whole column sum721 forgets the ten
7 436 + 464 900 890 forgets the ten8910 writes the whole column sum990 carries two columns over
8 334 + 419 753 7413 writes the whole column sum743 forgets the ten843 carries two columns over
9 17 + 34 51 41 forgets the ten411 writes the whole column sum
10 296 + 591 887 1787 carries two columns over7187 writes the whole column sum787 forgets the ten
11 279 + 219 498 4818 writes the whole column sum488 forgets the ten588 carries two columns over
12 24 + 68 92 812 writes the whole column sum82 forgets the ten
13 15 + 17 32 212 writes the whole column sum22 forgets the ten
14 148 + 259 407 3917 writes the whole column sum397 forgets the ten497 carries two columns over
15 290 + 391 681 1581 carries two columns over5181 writes the whole column sum581 forgets the ten
16 56 + 39 95 815 writes the whole column sum85 forgets the ten
17 168 + 575 743 1733 carries two columns over61313 writes the whole column sum633 forgets the ten
18 418 + 308 726 7116 writes the whole column sum716 forgets the ten816 carries two columns over
19 186 + 194 380 1370 carries two columns over21710 writes the whole column sum270 forgets the ten
20 29 + 18 47 317 writes the whole column sum37 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.