Mathematics
Addition & Subtraction
Procedural
9–10 yrs
Adding and subtracting (age 9+)
加法与减法（9岁以上）
Description
Solve addition and subtraction multi-step problems in contexts, deciding which operations and methods to use and why
Mastery Evidence
- A school collects 12,450 bottles in Week 1 and 8,372 in Week 2; their target is 25,000 — how many more do they need?
- Choose between mental and written methods for each step and explain why
- Solve a three-step problem involving addition and subtraction of five-digit numbers
Assessment Prompt
If your child is given a multi-step problem — like planning a budget where money is added and spent in several steps — can they decide which operations to use at each stage and explain their thinking?
