Idea 5of 22Builds onThree ways to write a ratio
The order of a ratio matters
Does it matter which number of a ratio comes first?
Today you'll discover
- how the words set the order
- why 3 : 2 and 2 : 3 differ
- how to turn a ratio round
Think firstOrange to blue is 3 : 2
What is the ratio of blue counters to orange counters?
Decide first, then press Next. Read the words before the numbers.
3 orange circles and 2 blue squares with the line orange to blue equals 3 to 2, then the line blue to orange equals 2 to 3. Then a tray of 2 orange and 3 blue, mostly blue; then 5 orange and 2 blue written both ways. The last step shows 1 orange and 4 blue.
See the whole ideathe big idea and the key word, in one place
The big idea
The order of a ratio matters: the amount named first has its term first.
Easy to get wrong3 : 2 and 2 : 3 are not the same. 3 orange for every 2 blue is mostly orange; 2 orange for every 3 blue is mostly blue.
Juice1 cup of juice for every 4 cups of water is juice to water, 1 : 4. Water to juice is 4 : 1.
Key word
- order of a ratio
- which amount is named first; its number is written first
Ready to use it?
- Write a ratio in the order the words give.
- Turn a ratio round when the question turns round.