# Mental and written addition and subtraction

Solve addition and subtraction problems using mental and written methods, including problems involving numbers, quantities, and measures

Builds on: Adding two two-digit numbers (hard, https://ai.page/c/adding-two-two-digit-numbers/en.md), Early Word Problems (soft, https://ai.page/c/early-word-problems/en.md)

Concept id: mental-and-written-addition-and-subtraction. Subject: maths. Licence: CC BY-SA 4.0.

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