Mathematics
Addition & Subtraction
Procedural
7–8 yrs
Missing number problems (age 7+)
缺失数字问题（7岁以上）
Description
Solve addition and subtraction problems including missing-number problems, using number facts, place value, and more complex methods
Mastery Evidence
- Solve a missing-number problem such as 245 + ? = 380
- Choose an appropriate method (mental, written, or combination) based on the numbers
- Solve multi-step problems combining addition and subtraction of three-digit numbers
Assessment Prompt
Can your child work out sums with a hidden number — like '? − 38 = 24' or '53 + ? = 91' — by thinking carefully about what the equation is asking?
