--- title: "Explaining Mathematical Reasoning" description: "With teacher prompting, explain and justify mathematical reasoning using drawings, number sentences, or words" canonical: https://lightmysky.com/learn/mathematics/explaining-mathematical-reasoning-mt_kJ5wYzO8qC source: https://lightmysky.com/learn/mathematics/explaining-mathematical-reasoning-mt_kJ5wYzO8qC.md retrieved: 2026-10-19 --- > **Agent view.** This is the Markdown twin of the page, for tools and assistants. > When to use this site, and the call that answers each job: https://lightmysky.com/agent-instructions.md > API description (OpenAPI 3.1): https://lightmysky.com/openapi.json · Authentication: https://lightmysky.com/auth.md > Pricing: https://lightmysky.com/pricing.md · Catalog: https://lightmysky.com/llms.txt · Full catalog: https://lightmysky.com/llms-full.txt > Every machine-readable file on this domain: https://lightmysky.com/.well-known/ai-catalog.json > Ask for Markdown with `Accept: text/markdown`, a `.md` address, or `?mode=agent`. # Explaining Mathematical Reasoning With teacher prompting, explain and justify mathematical reasoning using drawings, number sentences, or words Subject: Mathematics · Area: Mathematical Thinking · Ages 6 to 7 Page: https://lightmysky.com/learn/mathematics/explaining-mathematical-reasoning-mt_kJ5wYzO8qC ## Ready when they can - Explain a solution strategy using a drawing or number sentence (e.g. 'I made ten first, then added the rest') - Justify why an answer is correct by showing an alternative method that gives the same result - Identify and explain an error in a worked example or a peer's solution ## Lesson: Telling how you got your answer Solving a math problem is only half the job. The other half is telling someone how you got there. You can use a drawing, a number sentence, or just words. **Example.** Mia has 8 stickers and gets 5 more. She explains: 'I made a ten first. 8 and 2 makes 10. Then I still have 3 left, so 10 and 3 makes 13.' *(drawing: Check it a different way. Start at 8 and count on 5 more: 9, 10, 11, 12, 13. Same answer as before.)* **Tip.** If a friend's answer looks wrong, look at their steps. Maybe they skipped a number or added the wrong parts. Checking someone's steps helps you find the mistake, not just the wrong answer. **Recap.** You can show your math thinking with a drawing, a number sentence, or words, and use it to check answers and find mistakes. ## Practice 18 questions on this page, each with its working shown. ## Needs first - [Showing Your Working](https://lightmysky.com/learn/mathematics/showing-your-working-mt_nyK25mNOeR) - [What the equals sign means](https://lightmysky.com/learn/mathematics/what-the-equals-sign-means-mt_oIzycTBeE4) - [Addition in any order](https://lightmysky.com/learn/mathematics/addition-in-any-order-mt_QCgbiVrwnp) ## Opens up - [Teaching It Back](https://lightmysky.com/learn/learning-to-learn/teaching-it-back-mt_6eTZUwKQZr) - [Justifying mathematical reasoning](https://lightmysky.com/learn/mathematics/justifying-mathematical-reasoning-mt_pyMD_SIiYO)