Math PicnicEvery sheet is a promise

Column addition & subtraction, step by step

Once single-digit facts are automatic, children line numbers up and work column by column.

Practice Practice sheetNew questions
The question

678 − 339

618 678 339 339
  1. 678 − 339, written in columns. Start at the RIGHT, with the ones.
  2. 8 is too small to take 9 from, so a ten comes across from the left: the ones now holds 18. 18 − 9 = 9.
  3. This column gave a ten to the right, so it is now 6, not 7. 6 − 3 = 3.
  4. 6 take away 3 leaves 3. Write it in the hundreds.
  5. That is the whole sum: 678 − 339 = 339.

How it works.

  1. 01

    678 − 339, written in columns. Start at the RIGHT, with the ones.

  2. 02

    8 is too small to take 9 from, so a ten comes across from the left: the ones now holds 18. 18 − 9 = 9.

  3. 03

    This column gave a ten to the right, so it is now 6, not 7. 6 − 3 = 3.

  4. 04

    6 take away 3 leaves 3. Write it in the hundreds.

  5. 05

    That is the whole sum: 678 − 339 = 339.

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