# Ratios & Percentages

### Topics

## Introduction to :

**Unit rate **is the ratio of *cost: number of units*. Then the ratio is simplified so that the number of units is 1.

Having a knack for unit rates can make you a smarter shopper. For example, let's say that you are craving some cheesy, crunchy goodness and are trying to decide between two bags of chips. The Shmoritos are $4.50 for 12 oz. Shmingles are $2.50 for 7.75 oz. You obviously want the most munch for your money, so which bag to buy?

To solve this crunchy conundrum, compare the *price per ounce* for each bag.

#### Which Chips are the Better Deal?

Shmoritos are | Shmingles are |

#### Unit Rate Example 1

Shmunkin Donuts offers a baker's dozen (13 doughnuts) for $4.94. What is the unit cost? |

#### Unit Rate Example 2

Your local grocery store is having a special on Vitamin Water. They are selling a 12-pack of 20 oz bottles for $11.50. The 32 oz bottles are also on sale for $1.45. Should you buy one 12-pack of 20 oz bottles or eight 32 oz bottles? | This one is a bit tricky because we can't compare the cost per bottle, since the bottles are different sizes. Instead, we need to compare the cost per total ounces. |

#### Unit Rate Exercise 1

A 12-pack box of Pop Shmarts costs $2.50. What is the cost per shmart?

#### Unit Rate Exercise 2

A 6-bar box of Grizzly Bear Granola Bars is $3.50. However, a 12-bar case of Wally’s Walnut Bars is $7.25. Which bar is the better buy?

#### Unit Rate Exercise 3

A bag of 45 Shmoreo cookies is $4.50. The bag of 30 Shmutter Butter cookies is $3.00. Which is the better buy?