# Finding a missing number in addition

Understand subtraction as finding an unknown addend (e.g. 10 − 8 = ? is the same as 8 + ? = 10)

Builds on: Addition as combining or putting together two (hard, https://ai.page/c/addition-as-combining-or-putting-together-two/en.md), Subtraction as taking away or separating (hard, https://ai.page/c/subtraction-as-taking-away-or-separating/en.md)

Concept id: finding-a-missing-number-in-addition. Subject: maths. Licence: CC BY-SA 4.0.

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