A ratio compares, it does not count
2 : 3 does not say there are 5 things. It says that for every 2 of the first there are 3 of the second — whether that is 2 and 3, or 20 and 30.
Class 5 to 8 · 27 games
Ratios, explained with pictures
Comparing two amounts by how many times one fits the other.
In everyday life: Two cups of rice to three cups of water, three boys to four girls in a group.
Scale both sides or you change the mix
Doubling a recipe means doubling everything. 2 : 3 becomes 4 : 6, not 4 : 3. Add to only one side and the taste changes.
A worked example
Is 4 : 6 the same mix as 2 : 3?
Yes
Both sides of 2 : 3 have been multiplied by 2. Nothing about the mix changed, only the amount you made.
Words to know
- ratio
- A comparison of two amounts, written like 2 : 3.
- equivalent ratios
- Ratios that describe the same mix, like 2 : 3 and 6 : 9.
In the games
You will match ratios that describe the same mix and spot the one that does not belong.
Skills
- Equivalent ratios · Class 6
- The unitary method · Class 7
- Direct and inverse proportion · Class 8
By class
Class 5 ratios (2) · Class 6 ratios (6) · Class 7 ratios (11) · Class 8 ratios (8)
Practise ratios in Tivumo
No download, no account for your child. Classes 3 to 12, more than 1,000 games.