Cardinal Math

Addition with regrouping · sheet 29 of 30

Answer key

The answer, and what a wrong answer means.

The sheet
#ProblemAnswerIf they wrote…
1 149 + 117 266 2516 writes the whole column sum256 forgets the ten356 carries two columns over
2 507 + 318 825 8115 writes the whole column sum815 forgets the ten915 carries two columns over
3 64 + 37 101 91 forgets the ten911 writes the whole column sum
4 19 + 17 36 216 writes the whole column sum26 forgets the ten
5 147 + 396 543 1533 carries two columns over41313 writes the whole column sum433 forgets the ten
6 45 + 18 63 513 writes the whole column sum53 forgets the ten
7 224 + 279 503 4913 writes the whole column sum493 forgets the ten593 carries two columns over
8 545 + 355 900 890 forgets the ten8910 writes the whole column sum990 carries two columns over
9 158 + 148 306 2916 writes the whole column sum296 forgets the ten396 carries two columns over
10 16 + 25 41 31 forgets the ten311 writes the whole column sum
11 581 + 173 754 1654 carries two columns over6154 writes the whole column sum654 forgets the ten
12 419 + 509 928 18 carries two columns over9118 writes the whole column sum918 forgets the ten
13 295 + 485 780 1770 carries two columns over61710 writes the whole column sum670 forgets the ten
14 680 + 160 840 1740 carries two columns over7140 writes the whole column sum740 forgets the ten
15 291 + 162 453 1353 carries two columns over3153 writes the whole column sum353 forgets the ten
16 46 + 47 93 813 writes the whole column sum83 forgets the ten
17 56 + 15 71 61 forgets the ten611 writes the whole column sum
18 14 + 16 30 20 forgets the ten210 writes the whole column sum
19 29 + 74 103 913 writes the whole column sum93 forgets the ten
20 149 + 777 926 1916 carries two columns over81116 writes the whole column sum816 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.