Mathematics·Addition & Subtraction·procedural
Fluent adding and subtracting within 20
Fluently add and subtract within 20 using mental strategies; know from memory all sums of two one-digit numbers
Suggested ages 7–8
Learning journey
Your child is advancing their calculation skills — learning to add and subtract larger numbers up to 1000, mastering mental math strategies, and solving more complex word problems.
Evidence of understanding
- 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 Fluent adding and subtracting within 20 instantly recall all the single-digit addition facts — like '7 + 8 = 15' — without needing to count or think for more than a second?
Standards alignment
2.OA.2US · ccss-math
Fluently add and subtract within 20
Common Core State Standards for Mathematics · 2