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3-digit addition worksheets
Hundreds-place columns with three addends by default — the stage where neat written method starts paying off.
Three-digit, multi-row addition rewards tidy columns and punishes sloppy ones, which is exactly why teachers assign it. The default here stacks three addends; take it to two for a gentler sheet or push rows higher for endurance work.
Strong students can try the same shape mentally on the practice pages — three-digit running sums are a signature mental-abacus skill.
Questions
Why three addends instead of two?
Two-addend three-digit sums are a small step from the two-digit stage; the third row is what forces carries to stack and columns to stay disciplined. Set rows to 2 if that is what your curriculum wants.
Is there a mental-math version of this?
Yes — the practice section has a free three-digit mental math drill with the same problem shape, no printing required.