Ratio
A mathematical relationship comparing the quantities of two different things.
Definition
A Ratio is a mathematical relationship comparing the quantities of two different things. It indicates how many times the first number contains the second.
Why It Matters
Ratios are used constantly in daily life. Baking a cake requires a specific ratio of flour to sugar. Mixing concrete requires a specific ratio of cement to water. If you understand the ratio, you can scale a recipe or a mixture up or down infinitely without ruining the result.
Ratios can be written in three different ways:
- With a colon: 3:1
- With the word "to": 3 to 1
- As a fraction: 3/1
Practical Example
Scaling a Recipe with Ratios
A pancake recipe calls for 2 cups of flour and 1 cup of milk. The ratio of flour to milk is 2:1.
If you want to feed a large crowd and you need to use 6 cups of flour, how much milk do you need? Because the ratio must stay 2:1, you simply maintain the proportion. For 6 cups of flour, you need 3 cups of milk.
Ratios are heavily used in finance as well, such as the Debt-to-Income Ratio.
Frequently Asked Questions
How do you write a ratio?
A ratio can be written with a colon (3:1), with the word "to" (3 to 1), or as a fraction (3/1).