Ratios
What are the ways to write ratios?
X:Y
X to Y
X/Y
An art teacher is stocking up on markers. It's $2 per marker pack, and they need 12 marker packs. They have $60. How much do they have left over?
You earn $36 mowing lawns for 4 hours. How much do you earn per hour?
$9 per hour
1:3
7:21
Are the ratios proportional?
Yes
What is a Ratio?
A comparison of two quantities using division
Write this ratio in a different way
3 to 8
3:8
3/8
The average rainfall rate in a rainforest
Write this as a numerical rate and a verbal rate.
Inches/Year
Inches per year
What is the unit rate?
24 dollars for 6 pounds
4 dollars per pound
4/1
How is this proportion read?
2:3 = 4/6
Two is to three as four is to six
What is a rate?
A Ratio of two quantities with different units
Write the ratio as a fraction in simplest form
35/120
7/24
It costs $400 for 100 square feet of artificial turf.
A golf course has 1600 square feet of land that needs fake grass. How much money does it cost?
$1600
You can rent a therapy snake for $7.25 per hour. How much does it cost to rent one for 5 hours?
$36.25
Do 6/4 and 8/12 form a proportion?
No
What is a unit rate?
A rate with a denominator of 1
Simplify this ratio. Round to the nearest whole number.
350 to 10
35 to 1
48 miles for every 8 gallons of gas.
Your tank holds 24 gallons of gas. How many miles can you travel with a full tank?
144 miles
Find the unit rate.
28 laps in 12 minutes
2 1/3
5/8 = 20/x
X = ?
X = 32
What is a proportion?
An equation stating that two ratios are equivalent
The ratio of males to females is 2 to 3
The ratio of females to males is 3 to 2
Are the statements equal?
Yes, because in both statements the amount of males is 2 and the amount of females is 3.
1/2 of red paint for every 3/4 cup of yellow paint
You need 5 1/4 cups of paint. How many cups of red paint do you need?
3 cups of red paint
It costs $68 for 16 square feet of flooring. How much does it cost for 12 square feet of flooring?
$51
Y/1 = 6/4
Y = ?
Y = 1.5
What are cross products and what can they be used to do?
An example cross product is
a/b = c/d
a X d = b X c
Cross products of a proportion are equal, and can be used to identify if a ratio is proportional