# CCSS.1.OA.B.4

subtraction, unknown addend, inverse relationship; interpret, solve, explain.

System: US Common Core Math
Route: /math/standards/us-ccss/curratom-us-ccss-1-oa-b-4
Skills: 2

## Skills and Examples

- [Equations Unknown Add Sub](/math/skills/oa/equations-unknown-add-sub) — Equations, Variables, Expressions, and Inequalities
- [Missing Addend Within 20](/math/skills/oa/missing-addend-within-20) — Whole-Number Operations and Fact Fluency