If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

### Course: Pre-algebra>Unit 3

Lesson 1: Intro to ratios

# Basic ratios

In this video, the instructor explains ratios using three examples: amusement park ride lines, Katie's book collection, and a picture of apples and bananas. Ratios compare two quantities and can be written as "a to b" or "a:b." The video demonstrates how to find and interpret ratios in various situations.

## Want to join the conversation?

• In real life I never used ratios, so my question is are ratios very useful?
• They are, and you've probably used them without even realising it. Ratios are intuitive and are the way we can compare different deals, extrapolate or scale things up and down.
• In real life I never used ratios, so my question is are ratios very useful?
• Ratios are very usefull in cooking.
For example, for every 2 cups of flours I need 1 cup of sugar. 2:1 ratio of flour to sugar.
• Do u have videos like this in Spanish my school does math in Spanish and the vocabulary is different making it a lot harder ?
• You can turn on Spanish subtitles.
• what does it really mean when Sal says for every blank there is blank
• it is just different way of say for example 3 to 4 so you could also do 3:4 or for every 3 there is 4. So it i just a different way to specify the problem. there are 3 different ways you can say or write it.
• why do we use ratios?
• to compare numbers in quantitative terms in real-world situations
• Did you know that you can plot ratios on a coordinate plane? I find that quite interesting!
• I tried to simplify the first question be couldn't.
• The ratio is 11 : 4, since the numbers share no common factors, there is nothing to simplify.
• Can a rate be converted into a ratio, and vice versa?