--- title: "Odd or Even" description: "Determine whether a group of objects (up to 20) has an odd or even number of members" canonical: https://lightmysky.com/learn/mathematics/odd-or-even-mt_hniI4E-OCE source: https://lightmysky.com/learn/mathematics/odd-or-even-mt_hniI4E-OCE.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`. # Odd or Even Determine whether a group of objects (up to 20) has an odd or even number of members Subject: Mathematics · Area: Number Representation & Place Value · Ages 7 to 8 Page: https://lightmysky.com/learn/mathematics/odd-or-even-mt_hniI4E-OCE ## Ready when they can - Pair objects and determine whether there is one left over (odd) or not (even) - Count a group by 2s to determine if the total is even - Write an equation to express an even number as a sum of two equal addends (e.g. 8 = 4 + 4) ## Lesson: Odd or even A group of things is even if you can put it into pairs with none left over. It is odd if one thing is left over with no partner. *(drawing: Pair up the dots: 4 pairs, none left over. 8 is even.)* *(drawing: Pair up the dots: 3 pairs, and 1 dot with no partner. 7 is odd.)* **Example.** Zoe has 10 buttons. She pairs them up: 2, 4, 6, 8, 10. Every button has a partner, so 10 is even. She can also write it as 5 + 5. **Tip.** Fast check: count by 2s. If you land exactly on the total, it is even. If you have one left over at the end, it is odd. **Recap.** Even means everything has a pair. Odd means one thing is left alone. ## Practice 18 questions on this page, each with its working shown. ## Needs first - [Odd and even numbers](https://lightmysky.com/learn/mathematics/odd-and-even-numbers-mt_0u4KLbvBa1) - [Counting in 2s, 5s and 10s](https://lightmysky.com/learn/mathematics/counting-in-2s-5s-and-10s-mt_nvdpxAJTBG) - [Addition as combining or putting together two groups](https://lightmysky.com/learn/mathematics/addition-as-combining-or-putting-together-two-groups-mt_OvyoRo47K-) ## Opens up - [Prime numbers](https://lightmysky.com/learn/mathematics/prime-numbers-mt_y1XCVsIelg)