Bell Work Write the ratio in simplest form: 18

1 / 17

# Bell Work Write the ratio in simplest form: 18 - PowerPoint PPT Presentation

Bell Work Write the ratio in simplest form: 18 24 Write the above ratio two other ways. What is the ratio of boys to girls and girls to boys in this class?. 3 4. 3 to 4; 3:4. Rates.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## Bell Work Write the ratio in simplest form: 18

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Bell Work

Write the ratio in simplest form: 18

24

Write the above ratio two other ways.

What is the ratio of boys to girls and girls to boys in this class?

3

4

3 to 4; 3:4

### Rates

A rate is a ratio of two quantities measured in different units.

Unit Rate

To find the Unit Rate, you would find the cost or amount for 1. Or the rate when the denominator is 1.

“How much for just 1?”

BACK

A unit rate is a rate that has a denominator of 1 unit. The three unit rates are equivalent.

15 mi

1 hr

15 mi/h

15 miles per hour

“per” means “for every”

Unit Rate

If it costs \$78 for 13 sandwiches, What is the unit rate?

BACK

Vocabulary
• A rate is a ratio that compares two quantities measured in different units.
• The unit rate is the rate for one unit of a given quantity. Unit rates have a denominator of 1.
Comparing Unit Prices
• Use division to find the unit prices of the two products in the question.
• The unit rate that is smaller (costs less) is the better value.

A store sells the same pasta the following two ways:

10 pounds of bulk pasta for \$15.00

2 pounds of packaged pasta for \$3.98

Bulk Pasta: \$15.00= \$1.50

10 lb 1 lb

Packaged Pasta:

\$3.98 = \$1.99

2 lb 1 lb

Which is the better buy? Find the unit price for both types.

The bulk pasta is the better buy because it costs less per pound.

Example

Joe’s car goes 25 miles per gallon of gasoline. How far can it go on 8 gallons of gasoline?

x 8

25 miles

=

Unit Rate

8 gallons

1 gallon

x 8

25 x 8 = 200. Joe’s car can go 200 miles on 8 gallons of gas.

The "Unit Price" (or "unit cost") tells you the cost per liter, per kilogram, per pound, etc, of what you want to buy. Just divide the cost by the quantity.

Price" (or "unit cost") tells you the cost per liter, per kilogram, per pound, etc, of what you want to buy.

Just divide the cost by the quantity:

Example: 2 liters for \$3.80 is \$3.80/2 liters = \$1.90 per liter

What is best?

10 pencils for \$4.00

or 6 pencils for \$2.70 ?

Here is the Unit Cost:

\$4.00 / 10 = \$0.40 per pencil

\$2.70 / 6 = \$0.45 per pencil

So the lowest Unit Price (and the best bargain) is 10 pencils for \$4.00

Comparing

Comparing Unit Prices can be a good way of finding which is the "best buy".

Example: What is best?

2 liters of Milk at \$3.80, or

1.5 liters of Milk at \$2.70 ?

In this case the "Unit" is 1 liter, and the Unit Prices are:

\$3.80 / 2 liters = \$1.90 per liter

\$2.70 / 1.5 liters = \$1.80 per liter

So the lowest Unit Price (and the best bargain) is 1.5 liters at \$2.70.

You buy a package of 6 pairs of athletic socks for \$8.94. Write this as a unit rate.

\$1.49 per pair

A bullet train in Japan can travel 186 miles in 2 hours. Write this as a unit rate.

93 mi/h

Cereal:17 ounces for \$3.40 or

14 ounces for \$3.08

17 ounces for \$3.40

Juice Anyone??

Juice is sold in two different sizes. A 48-fluid ounce bottle costs \$2.07. A 32-fluid ounce bottle costs \$1.64. Which is the better buy?

\$2.07

\$0.04 per fl.oz.

0.043125

48 fl.oz.

\$1.64

\$0.05 per fl.oz.

0.05125

32 fl.oz.

The 48 fl.oz. bottle is the better value.

Find the Unit Rate

Amy can read 88 pages in 4 hours. What is the unit rate? (How many pages can she read per hour?)

88 pages

22 pages / hour

4 hours

Heartbeats…

Rate:

150 heartbeats

2 minutes

Unit Rate (How many beats per minute)

150 ÷ 2 = 75 heartbeats per minute.

Practice: