A ratio is simply a comparison between two quantities, obtained by dividing one quantity by the other. Example: The ratio of boys to girls in the class was 4:5
A proportion is a name we give to a statement that two ratios are equal.
To be a proportion the cross products must be equal
To make 20 pancakes you have to use 2 eggs.
How many eggs are needed to make 80 pancakes?
20 •X = 80 •2
A rate is a ratio that is used to compare different kinds of quantities.
Unit rate is a ratio between 2 measurements in which the second term is 1
Unit Rates Unit Rate Unit Price Proportions (unit price)
Two variables are proportional if a change in one is always accompanied by a change in the other.
Ratios in Proportional Relationships Shadow Find the missing number
The relationship between the diameter and circumference of a circle
Measure the circumference and diameter of circular objects. Find the ratio of circumference to diameter for each object.
Ratio Relationship of π=C/d
Circumference and Area,
Find radius given area,
Solving Proportions Word Problems
Proportions with integers
Proportions with Decimals
Proportions in real life – WP3
Proportions in real life – WP6
Proportions in real life – WP10
Proportions in real life – WP11
Proportions in real life – WP13
Proportions in real life – WP15
Proportions in real life – WP16
Scale problems – WP38
Scale problems – WP39
Solving shadow proportions – WP41
Proportions in real life – WP42