--- title: "Ratio Notation" description: "Use ratio notation to describe the relationship between two or more quantities, simplify ratios to their simplest form, and convert between ratio and fraction representations" canonical: https://lightmysky.com/learn/mathematics/ratio-notation-mt_XWSGuFW7It source: https://lightmysky.com/learn/mathematics/ratio-notation-mt_XWSGuFW7It.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`. # Ratio Notation Use ratio notation to describe the relationship between two or more quantities, simplify ratios to their simplest form, and convert between ratio and fraction representations Subject: Mathematics · Area: Ratio & Proportion · Ages 11 to 12 Page: https://lightmysky.com/learn/mathematics/ratio-notation-mt_XWSGuFW7It ## Ready when they can - Write a ratio from a word problem and simplify it (e.g. 12:8 = 3:2) - Convert a ratio to equivalent fractions of a whole (e.g. 3:2 means 3/5 and 2/5) - Simplify ratios involving decimals or fractions by finding a common multiplier ## Lesson: Ratio Notation: Comparing Two Amounts A ratio compares two amounts using a colon, like 3:2. It means that for every 3 parts of the first amount, there are 2 parts of the second amount. Order matters: 3:2 is not the same as 2:3. *(drawing: For every 3 cups of orange juice, there are 2 cups of mango juice.)* To simplify a ratio, divide every number in it by their greatest common factor. For the ratio 12:8, the greatest common factor of 12 and 8 is 4, so dividing both by 4 gives 3:2. **Example.** A ratio also tells you the fraction each part makes of the whole. For the ratio 3:2, add the parts together: 3 + 2 = 5. That means the first amount is 3/5 of the total, and the second amount is 2/5 of the total. **Tip.** If a ratio has decimals or fractions, multiply both numbers by the same value first to make them whole numbers, then simplify as usual. For example, 1.5:3 becomes 3:6 after multiplying by 2, which simplifies to 1:2. **Recap.** Write a ratio with a colon in the correct order, simplify it by dividing both numbers by their greatest common factor, and turn it into fractions by putting each part over the total number of parts. ## Practice 15 questions on this page, each with its working shown. ## Needs first - [Ratio and proportion vocabulary](https://lightmysky.com/learn/mathematics/ratio-and-proportion-vocabulary-mt_ESgc4YBw-a) - [Factors, multiples, and primes](https://lightmysky.com/learn/mathematics/factors-multiples-and-primes-mt_FHIAv6dfhU) - [Unequal sharing and grouping](https://lightmysky.com/learn/mathematics/unequal-sharing-and-grouping-mt_FnUJMXPUZX) ## Opens up - [Proportional Reasoning Vocabulary](https://lightmysky.com/learn/mathematics/proportional-reasoning-vocabulary-mt_ATYLKt0je-) - [Proportion Graphs](https://lightmysky.com/learn/mathematics/proportion-graphs-mt_FspV_imUGK) - [Dividing Quantities by Ratio](https://lightmysky.com/learn/mathematics/dividing-quantities-by-ratio-mt_nOCPx5qw0Z) - [Similarity and enlargement](https://lightmysky.com/learn/mathematics/similarity-and-enlargement-mt_y-BuQAfw4B) - [Ratio Notation and Relationships](https://lightmysky.com/learn/mathematics/ratio-notation-and-relationships-mt_yK51ZnKA8m)