Hey there! Today we are exploring ratios, which are just a cool way to compare different amounts. Let's see how they work!
A ratio is a comparison of two numbers. It tells us how much of one thing we have compared to another thing, like comparing apples to oranges in a fruit bowl.
Let's look at a simple ratio of red gems to blue gems. If we have 1 red gem for every 3 blue gems, we can write this ratio as 1:3.
Ratios can be scaled up! If we double both parts of our 1:3 ratio, we get 2 red gems and 6 blue gems. The relationship stays exactly the same.
✏️ Worked example
A recipe for lemonade calls for 2 cups of lemon juice for every 5 cups of water. If you want to make a bigger batch using 6 cups of lemon juice, how many cups of water do you need?
Identify the starting ratio of lemon juice to water, which is 2:5.
See how the lemon juice changed: it went from 2 cups to 6 cups.
Determine the multiplier: 6 divided by 2 is 3. We multiplied the lemon juice by 3!
To keep the ratio equal, multiply the water by the same number: 5 cups of water times 3 is 15.
You will need 15 cups of water for your big batch of lemonade.
Want the full interactive lesson — quiz, animations, and Finn cheering them on?
Studyfin
✨ Sign up free
