Idea 1of 22
A ratio compares two amounts
What does a ratio tell you about two amounts?
Today you'll discover
- what “for every” means
- how one group shows a ratio
- why a bigger tray can keep the same ratio
Think first2 orange counters and 3 blue counters
Which sentence compares the orange and blue counters as a ratio?
Decide first, then press Next. Count each colour inside one box.
Orange circles and blue squares on a tray. First 2 orange and 3 blue, loose; then packed into one dashed box. Then 4 orange and 6 blue packed into two boxes, each holding 2 orange and 3 blue, with the line orange to blue equals 4 to 6, the same as 2 to 3. 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
A ratio compares two amounts, like 2 orange for every 3 blue.
Compare themA difference says how many more. A ratio says how many go together. Double the tray and there are 2 more blue, but still 2 orange for every 3 blue.
Ratios around you3 cups of water for every 1 scoop of juice crystals. 2 adults for every 15 students on a class trip.
Key word
- ratio
- a comparison of two amounts, like 2 orange for every 3 blue, written 2 : 3
Ready to use it?
- Say a ratio with the words “for every”.
- Find the ratio of two colours of counters.