Cardinal Math

Addition with regrouping · sheet 3 of 30

Answer key

The answer, and what a wrong answer means.

The sheet
#ProblemAnswerIf they wrote…
1 789 + 184 973 1963 carries two columns over81613 writes the whole column sum863 forgets the ten
2 661 + 162 823 1723 carries two columns over7123 writes the whole column sum723 forgets the ten
3 148 + 107 255 2415 writes the whole column sum245 forgets the ten345 carries two columns over
4 15 + 57 72 612 writes the whole column sum62 forgets the ten
5 207 + 276 483 4713 writes the whole column sum473 forgets the ten573 carries two columns over
6 615 + 288 903 8913 writes the whole column sum893 forgets the ten993 carries two columns over
7 14 + 49 63 513 writes the whole column sum53 forgets the ten
8 319 + 219 538 5218 writes the whole column sum528 forgets the ten628 carries two columns over
9 198 + 608 806 7916 writes the whole column sum796 forgets the ten896 carries two columns over
10 667 + 184 851 1841 carries two columns over71411 writes the whole column sum741 forgets the ten
11 191 + 160 351 1251 carries two columns over2151 writes the whole column sum251 forgets the ten
12 22 + 38 60 50 forgets the ten510 writes the whole column sum
13 11 + 19 30 20 forgets the ten210 writes the whole column sum
14 53 + 49 102 912 writes the whole column sum92 forgets the ten
15 47 + 56 103 913 writes the whole column sum93 forgets the ten
16 486 + 258 744 1734 carries two columns over61314 writes the whole column sum634 forgets the ten
17 373 + 329 702 6912 writes the whole column sum692 forgets the ten792 carries two columns over
18 45 + 28 73 613 writes the whole column sum63 forgets the ten
19 288 + 391 679 1579 carries two columns over5179 writes the whole column sum579 forgets the ten
20 14 + 19 33 213 writes the whole column sum23 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.