3 digit addition worksheets
Twenty three-digit addition problems — column addition at full size, carrying included.
Best fit: 2nd–3rd grade · Answer key included · Free, no sign-up
Answer key
The same sheet with every answer shown in blue — print it for marking, or hand it over for self-checking.
About these worksheets
Three-digit addition is where the column algorithm proves its worth: the same right-to-left, carry-when-you-must routine, now across hundreds, tens and ones. This set mixes problems that carry once, twice, or not at all, so students must attend to every column. Sums can pass 1,000, which is its own small thrill.
Need a different set?
The generator makes unlimited versions of this worksheet — choose the operation and difficulty, and every click is a brand-new sheet with its own answer key.
Frequently asked questions
Does this include carrying across hundreds?
Yes — the mix includes single carries, double carries and no-carry problems, in random order.
What grade is 3-digit addition?
Late 2nd grade and 3rd grade in most US curricula, right after two-digit addition is fluent.
Can I get bigger or smaller numbers?
The generator makes single-digit through 3-digit versions of this exact layout, each with a key.