Cardinal Math

Addition with regrouping · sheet 6 of 30

Answer key

The answer, and what a wrong answer means.

The sheet
#ProblemAnswerIf they wrote…
1 199 + 199 398 1388 carries two columns over21818 writes the whole column sum288 forgets the ten
2 294 + 311 605 1505 carries two columns over505 forgets the ten5105 writes the whole column sum
3 159 + 449 608 5918 writes the whole column sum598 forgets the ten698 carries two columns over
4 63 + 28 91 81 forgets the ten811 writes the whole column sum
5 109 + 698 807 7917 writes the whole column sum797 forgets the ten897 carries two columns over
6 449 + 258 707 6917 writes the whole column sum697 forgets the ten797 carries two columns over
7 87 + 18 105 915 writes the whole column sum95 forgets the ten
8 419 + 325 744 7314 writes the whole column sum734 forgets the ten834 carries two columns over
9 472 + 191 663 1563 carries two columns over5163 writes the whole column sum563 forgets the ten
10 241 + 299 540 1530 carries two columns over41310 writes the whole column sum430 forgets the ten
11 478 + 453 931 1921 carries two columns over81211 writes the whole column sum821 forgets the ten
12 509 + 275 784 7714 writes the whole column sum774 forgets the ten874 carries two columns over
13 62 + 39 101 91 forgets the ten911 writes the whole column sum
14 14 + 16 30 20 forgets the ten210 writes the whole column sum
15 57 + 37 94 814 writes the whole column sum84 forgets the ten
16 780 + 121 901 1801 carries two columns over801 forgets the ten8101 writes the whole column sum
17 15 + 15 30 20 forgets the ten210 writes the whole column sum
18 19 + 51 70 60 forgets the ten610 writes the whole column sum
19 105 + 509 614 6014 writes the whole column sum604 forgets the ten704 carries two columns over
20 11 + 59 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.