Vocabulary
A comparison of two numbers is....
Ratio
There are 2 cats and 3 dogs. Write the ratio of cats to dogs.
2:3
3 pencils cost $6. How much is 1 pencil?
2$
Solve: 1/2 = x/6
x = 3
A rate that compares something to...
Write 4 red markers to 5 blue markers as a ratio.
4:5
4 drinks cost $8. Cost per drink?
2$
Solve: 2/3 = x/9
x = 6
Two ratios that are equal
Proportion
There are 6 girls and 3 boys. Ratio of girls to boys?
6:3
You travel 12 miles in 3 hours. Miles per hour?
4 mph
Solve: 3/5 = x/10
x = 6
The method where we cross multiply to solve a proportion..
Butterfly Method
A bag has 8 red and 4 blue candies. Ratio of blue to red candies?
8:4
5 notebooks cost $15. Cost per notebook?
$3
Solve: 4/6 = x/12
x = 8