{"system":{"system_id":"us_ccss","public_slug":"us-ccss","label":"US Common Core Math","official_source_urls":["https://thecorestandards.org/Math/","https://thecorestandards.org/standards-in-your-state/"]},"standard":{"system_id":"us_ccss","system_slug":"us-ccss","system_label":"US Common Core Math","code":"CCSS.1.OA.B.4","label":"subtraction, unknown addend, inverse relationship; interpret, solve, explain.","public_slug":"curratom-us-ccss-1-oa-b-4","route":"/math/standards/us-ccss/curratom-us-ccss-1-oa-b-4","data_json_route":"/math/data/standards/us-ccss/curratom-us-ccss-1-oa-b-4.json","data_markdown_route":"/math/data/standards/us-ccss/curratom-us-ccss-1-oa-b-4.md","skill_count":2,"skills":[{"title":"Equations Unknown Add Sub","route":"/math/skills/oa/equations-unknown-add-sub","family_name":"Equations, Variables, Expressions, and Inequalities","standards":[]},{"title":"Missing Addend Within 20","route":"/math/skills/oa/missing-addend-within-20","family_name":"Whole-Number Operations and Fact Fluency","standards":[]}],"crawler_summary":"CCSS.1.OA.B.4 maps to 2 math skills."}}