Mathematics
Addition & Subtraction
Procedural
7–8 yrs
Fluent adding and subtracting within 20
20以内加减法流利运算
Description
Fluently add and subtract within 20 using mental strategies; know from memory all sums of two one-digit numbers
Mastery Evidence
- Answer any single-digit addition fact within 3 seconds
- Recall subtraction facts within 20 from memory (e.g. 15 − 8 = 7)
- Use known addition facts to derive related subtraction facts rapidly
Assessment Prompt
Can your child instantly recall all the single-digit addition facts — like '7 + 8 = 15' — without needing to count or think for more than a second?
