Grades 1–2 · 2.NBT.5, 2.NBT.7 · sheet 9 of 30
Addition with regrouping
A printable worksheet, new every day, with a key that names the mistake.
- Eight two-digit sums and twelve three-digit ones, carrying in the ones, the tens, both, and the cascade where one carry causes the next.
- The key lists the three ways a carry goes wrong: forgotten, written into the answer, or sent to the wrong column.
Addition with regrouping
Show your work. Ten ones make a ten; carry it.
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1
296 +392
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2
15 +56
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3
197 +139
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4
56 +46
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5
56 +25
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6
289 +113
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7
33 +29
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8
189 +539
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9
586 +299
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10
390 +452
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11
109 +199
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12
134 +148
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13
448 +170
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14
217 +309
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15
22 +19
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16
32 +69
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17
318 +524
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18
13 +49
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19
243 +258
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20
33 +18
The app does this live.
It picks the next problem from the last answer, skips ahead or doubles back, and animates the teaching instead of handing over a rule. The five-minute check on the guide is the same engine in your browser, and the guide explains each of the patterns the key names.
How to use the key
Mark the sheet against the key. Beside each answer it lists what the known mistakes would have written. One wrong answer is a slip. The same pattern three times is a rule your child is following, and the guide says what to do about it tonight.
On this sheet the key can tell apart: writes the whole column sum (20 problems), forgets the ten (20 problems), carries two columns over (12 problems).
Cardinal Math watches for all of these, every day.
Inside the app the same patterns are caught as your child plays, across the whole of K to grade 5, and explained to you in plain words. One price, no ads, no streaks. Coming to iPhone and iPad.
Tell me when it's out