Unit Rates
A student reads 6 pages in 2 minutes. How many pages do they read in 1 minute?
If you divide the minutes and pages by 2, the student reads 3 pages per minute.
Write 1 more Equivalent Ratio:
3:12
1:4
Are the Ratios Equivalent?
2/4 = 3/5
No! You are not multiplying the numerator and denominator by the same number. You can't add a number to the numerator and denominator and say it's equivalent.
Solve for x to make the Ratios Equivalent:
x/5 = 8/10
x = 4
A box of cereal sates there are 90 calories in a 1-cup serving. How many calories are there in 3 cups of cereal?
If we multiply the unit rate by 3 we find that 90 calories times 3 means there is 270 calories in 3 cups of cereal.
Write 1 more Equivalent Ratio:
18:4
9:2
Are the Ratios Equivalent?
5/10 = 3/6
Yes! These fractions are both worth 1/2 of something. You are multiplying the numerator and denominator by the same number.
Solve for x to make the Ratios Equivalent:
3/9 = 9/x
x = 27
The recipe that I am making calls for 3 cups of sugar for every 1 cup of butter. How much butter will I need if I triple my recipe?
Triple means three times, so we need to multiply the 1 cup of butter by 3 and we get 3 cups of butter.
Write 2 more Equivalent Ratios:
10:20
1:2, 2:4
Are the Ratios Equivalent?
8/10 = 16/18
No! You are NOT multiplying the numerator and denominator by the same number. 8 times 2 equals 16 but 10 times 2 does NOT equal 18.
Solve for x to make the Ratios Equivalent:
7/14 = x/42
x = 21
A car goes about 14 miles on a 1/2 gallon of gas. How far can the car go on 1 gallon of gas?
The reciprocal of 1/2 is 2/1 so if we multiply the 1/2 gallon of gas and the 14 miles by 2 we find that the car can go 28 miles on 1 gallon of gas.
Write 3 more Equivalent Ratios:
15:30
1:2, 3:6, 5:10
Are the Ratios Equivalent?
13/14 = 39/42
Yes! You are multiplying the numerator and denominator by the same number: 3/3
Solve for x to make the Ratios Equivalent:
2/16 = x/80
x = 10
Jose goes into his favorite candy store. The sign reads that all candy is $2.99 for a quarter pound. How much is 1 pound of candy?
A quarter of a pound is 1/4, so 1/2 pound would cost $5.98, 3/4 pound would cost $8.97- and 1-pound cost $11.96. To get 1/4 to equal 1 you have to multiply by the reciprocal so you need to multiply 1/4 and 2.99 times 4/1
!!!!DAILY DOUBLE!!!!
Write 3 more Equivalent Ratios:
24:72
12:36, 8:24, 6:18, 3:9, 4:12
Are the Ratios Equivalent?
8/32 = 56/224
Yes! You are multiplying the numerator and denominator by the same number: 7/7
!!!!DAILY DOUBLE!!!!
Solve for x to make the Ratios Equivalent:
18/x = 54/90
x = 30