{"schema_version":"teacher-skill-representation.payload.v1","representation":{"schema_version":"teacher-skill-representation.v1","skill_ref":"oa.sub.within-20.strategies","domain_slug":"oa","skill_slug":"sub-within-20-strategies","canonical_url":"/math/skills/oa/sub-within-20-strategies","public_title":"Sub Within 20 Strategies","family_ref":"module-family.oa.whole-number-operations-fluency.v1","family_name":"Whole-Number Operations and Fact Fluency","pattern_cluster_refs":[],"task_pattern_refs":[],"task_form_refs":[],"teacher_summary":"Sub Within 20 Strategies builds whole-number operations and fact fluency through visual tasks, examples, and next-step routes.","teacher_explanation_md":"Sub Within 20 Strategies practice with visual examples, common slips, and next-step routes.","child_surface_summary_md":"Sub Within 20 Strategies uses short visual tasks with clear answer actions and repairable mistakes.","common_mistake_tags":["Count back off by one.","Subtracts smaller digit from larger.","Ten bridge wrong split.","Misses related addition."],"hint_reveal_summary_md":"Hints keep the child oriented to the visible structure; reveals show the path without counting as independent evidence.","adaptation_summary_md":"Fresh independent work can move the child toward Core, Transfer, or Challenge routes; help use or confusion keeps support visible.","route_variant_refs":[],"age_band_refs":["age_6_7","age_8_9","age_10_11"],"practice_focus_refs":["practice-focus.balanced.v1","practice-focus.math-facts-times-tables.v1","practice-focus.number-sense-place-value.v1"],"standards_refs":[],"school_program_refs":[],"challenge_refs":[],"story_fit_tags":[],"prerequisite_skill_refs":[],"next_skill_refs":[],"next_family_refs":["module-family.oa.models-word-problems.v1","module-family.prealg.equations-expressions-inequalities.v1","module-family.frac.parts-wholes-fair-shares.v1"],"public_example_refs":[],"retrieval":{"aliases":["Sub Within 20 Strategies","oa.sub.within-20.strategies","Whole-Number Operations and Fact Fluency"],"teacher_questions":["What does Sub Within 20 Strategies mean?","How does Sub Within 20 Strategies adapt for my child?","Can I see an example of Sub Within 20 Strategies?"],"keywords":["sub within 20 strategies","oa","sub-within-20-strategies","whole-number operations and fact fluency"],"short_answer_public":"Sub Within 20 Strategies builds whole-number operations and fact fluency through visual tasks, examples, and next-step routes.","canonical_links":[{"label":"Sub Within 20 Strategies","url":"/math/skills/oa/sub-within-20-strategies"}],"safe_to_quote_snippets":["Sub Within 20 Strategies builds whole-number operations and fact fluency through visual tasks, examples, and next-step routes."],"example_refs":[]}},"task_forms":[],"examples":[],"preview_artifacts":[]}