Ratios:
Learning intention- Use models and diagrams to investigate ratios
Connect- Here is a collection of models.
(Insert picture)
Learning intention- Use models and diagrams to investigate ratios
Connect- Here is a collection of models.
(Insert picture)
- We can use a ratio to compare one part of the collection to the whole
collection.
There are 9 cars compared to 13 models.
The ratio of cars to models is written as 9 to 13 or 9:13. - We can use a ratio to compare one part of the
collection to another part. (Part to whole)
There are 9 cars compared to 4 planes.
The ratio of cars to planes is written as 9 to 4 or 9:4.
9 and 4 are called the terms of the ratio.
9 is the first term and 4 is the second. (Part to part)
Example
At a class party, there are 16 boys, and 15 girls, and 4 adults. What is each ratio?
- boys to girls
- girls to adults
- adults to the total number of people at the
party
- There are 16 boys and 15 girls
So, the ratio of boys to girls is 16:15 - There are 15 girls and 4 adults
So the ratio of girls to adults is 15:4 - The total number of people is 16+15+4=35
So, the ratio of adults to total number of people is 4:35.