--- title: "The teen numbers" description: "Understand that the teen numbers (11–19) are composed of ten ones and some further ones (early place value)" canonical: https://lightmysky.com/learn/mathematics/the-teen-numbers-mt_xmmgAzxe5j source: https://lightmysky.com/learn/mathematics/the-teen-numbers-mt_xmmgAzxe5j.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`. # The teen numbers Understand that the teen numbers (11–19) are composed of ten ones and some further ones (early place value) Subject: Mathematics · Area: Number Representation & Place Value · Ages 5 to 7 Page: https://lightmysky.com/learn/mathematics/the-teen-numbers-mt_xmmgAzxe5j ## Ready when they can - Compose 14 as a group of ten and four ones using objects - Decompose 17 into 10 + 7 and record as an equation - Explain that 13 is 'one ten and three ones' ## Lesson: Teen numbers: a ten and some more You already know how to count and read numbers past ten. Now look closer at numbers like 11 to 19. Each teen number is one full ten, plus a few more ones. *(drawing: 14 blocks: one full group of ten, and four more ones.)* **Example.** Sam has 16 cubes. He puts ten cubes in one tower. Six cubes are left over. Ten and six make sixteen. A teen number is written with two digits. The 1 in front does not mean one block. It stands for the whole ten. The digit after it counts the extra ones. In 16, the 1 is Sam's ten and the 6 is the six left over. You can write that as 16 = 10 + 6. The plus joins the parts, and both sides show the same number. When you see a teen number, picture the ten as already made, then count only the extra ones. On a number line, jump straight to 10, then hop the extra ones. You never have to count from 1. **Recap.** Every teen number is one ten and some more ones. ## Practice 30 questions on this page, each with its working shown. ## Needs first - [Reading +, −, and = symbols](https://lightmysky.com/learn/mathematics/reading-and-symbols-mt_8RmpkDxT9L) - [Reading and writing numbers to 20](https://lightmysky.com/learn/mathematics/reading-and-writing-numbers-to-20-mt_fR0UtsSREU) ## Opens up - [The two digits of a two-digit number](https://lightmysky.com/learn/mathematics/the-two-digits-of-a-two-digit-number-mt_THl9GLxwoL) - [Spotting mathematical patterns](https://lightmysky.com/learn/mathematics/spotting-mathematical-patterns-mt_uG2mjHFOlO)