Use this page when you want 3 digit addition without regrouping worksheets in the next thirty seconds: choose how many problems you want, press print, and the answer key comes out on its own page behind the worksheet. The current sheet starts with problems like 477 + 201 and 366 + 301, and the answers (678 and 667) are printed on the key so marking takes about a minute.
‘New set of problems’ opens the generator in its own tab. There you can change the problem count and turn the answer key on or off. ‘Print or save as PDF’ opens the print dialog — choose Save as PDF in the printer list to keep the file. The sheet fits US Letter and A4, and the answer key prints on its own page.
Because the addends are regenerated every time, a child cannot learn the sheet instead of the skill. Yesterday's page may have asked for 584 + 214; today's asks something else in the same shape.
What separates a confident adder from a slow one is rarely the method; it is whether the number bonds underneath are automatic. Watch how long the child hesitates before writing the first digit of 667.
Written addition is worth practising in columns — which is what these 3 digit addition without regrouping worksheets ask for — even when a child working at this level can do it mentally, because the column layout is what makes four-digit work manageable later. A problem such as 268 + 301 is small enough to do mentally and worth writing out anyway.
Fluency in addition is usually described in two parts: knowing the single-digit facts by recall, and applying a written method to bigger numbers. This sheet exercises whichever of the two the number range implies — for 477 + 201 the answer 678 should come from memory, not from counting.
These 3 digit addition without regrouping worksheets are commonly aligned with the addition strand of most US state standards for this grade, and the skill appears in most curricula somewhere around this point.
| # | Problem | Answer | What to check |
|---|---|---|---|
| 1 | 477 + 201 = | 678 | Watch for: treating a longer number as a bigger one |
| 2 | 366 + 301 = | 667 | Check: counting on from the wrong number |
| 3 | 584 + 214 = | 798 | Look at: guessing on the near-tens |
| 4 | 268 + 301 = | 569 | Ask about: losing the place columns |
| 5 | 718 + 161 = | 879 | Watch for: forgetting the carried digit |
| 6 | 671 + 325 = | 996 | Check: adding right to left, then reading left to right |
Here is one worked through. 366 + 301 gives 667. If your child arrives somewhere other than 667 on 366 + 301, look at the working rather than the answer: nearly every wrong result comes from a skipped step, not an unknown fact.
Try 584 + 214 together before letting the child start alone. The answer to 584 + 214 is 798, and talking through how it was reached takes about a minute and saves several minutes of guessing later in the sheet.
Because the numbers are random, there is no shared answer list to look up: the key printed behind your sheet is the only one that fits it, and it shows 678 for 477 + 201.
The answer key is generated with the worksheet, not written by hand, so it always matches the sheet in front of you — 477 + 201 is listed as 678, 366 + 301 as 667, and so on down the page.
To save these 3 digit addition without regrouping worksheets instead of printing them, choose 'Save as PDF' in the printer list. You get the worksheet and the answer key as a single PDF, on Letter or A4 depending on your printer settings.
If the problems look cramped, drop the count from 20 to a smaller number before printing these 3 digit addition without regrouping worksheets; the font stays the same size and the spacing opens up.
When these become easy, move along the related links below rather than adding more problems to the same sheet.
Free printable math worksheets from a working math academy director in Korea. Problems come from our own code, not from a published workbook. Every sheet prints on US Letter or A4 with its answer key. All worksheets · Worksheet generator · Korean site
Last updated: 2026-09-13