Confidential 2

Convert the following decimals to percent:

1. 0.75 = 75%2. 0.0095 = .95%3. 0.439 = 43.9%4. 0.422 = 42.2%5. 0.87 = 87%

Warm up

Confidential 3

Let’s Review what we have learned in the last

lesson• The decimal point separates the whole units on

the left from the decimal units on the right.  • The numbers on the left side represent whole num

bers.• The numbers on the right side of the point are the

decimal values.

• The naming difference is in the "th“

• Percent means parts per hundred. • we use the symbol % for percent.

Confidential 4

• For converting decimals to percent •Multiply the decimal by 100 and put the %

sign

• For converting percent to decimals •First remove the Percent sign. •Divide by 100

Recap

Confidential 5

What is rate/unit rate?

A rate is a ratio that is used to compare different kinds of quantities.

A unit rate describes how many units of the first type of quantity corresponds to one unit of the second quantity.

Examples of unit rates: miles per hour, kilometers per hour, meter per seconds, cost per item, earnings per week, etc.

Confidential 6

Finding unit priceA unit price is a rate comparing the

price of an item to its unit of measure. To find the unit price of an item divide the

total cost by the number of items bought.

After finding the unit price we can also find the cost of more than one item– Multiply the unit price by the number of

items you are buying

Confidential 7

Price of 5 apples is $20. Find the unit price and find the price of 7 apples.

Unit price = 20/5 = $4 Price of 7 apples = 7 × 4 = $28 The price of 7 apples is $28.

To find the unit Price divide total cost by the number of items bought .

Example 1

Confidential 8

John can type 923 words in 13 minutes. Find how many words per minute can he type.

Unit rate = 923/13 = 71

John can type 71 words per minutes.

To find the unit rate divide total words by the number of minutes.

Example 2

Confidential 9

Distance, rate and time

Distance = Rate × time– To find distance multiply rate by time

Rate = Distance/time– To find rate divide distance by time

Time = Distance/rate– To find time divide distance by rate

Confidential 10

On a trip, Kate traveled 600 km. for 10 hours. Find her average speed?

Average Speed = Rate Rate = Distance/time Rate = 600/10 = 60 km. per hour

Kate’s average speed was 60 km./hour.

To find the rate divide distance by time .

Example 3

Confidential 11

Your Turn

Find the unit rate:

1. 72 seats in 9 rows 8 seats2. 160 miles in 5 hours 32mi/h3. 70 seats in 5 rows 14 seats4. 192 pages in 4 days 48 pages5. 320 meters in 5 seconds 64 m /s

Confidential 12

Your Turn

Find the unit rate:

6. 143 seats in 13 rows 11 seats7. 300 miles in 6 hours 50mi/h8. 350 words in 5 minutes 70 words9. 70 steps in 2 minutes 35 steps10.240 meters in 6 seconds 40 m /s

Confidential 13

Confidential 14

Let us play a game

Click here to play

Confidential 15

1) Maria works in a book store and she earns $100 for 5hours of work. i) At this rate, how much would she earn in 8

hours?

ii) How many hours would it take to earn $250?

i) First find Maria's rate per hour. Rate per hour = 100/5 =$20 Earnings for 8 hours = 20 × 8 =$160

Confidential 16

ii) Divide total earnings by the rate. No. of hours = 260/20 = 13 hours

Maria worked for 13 hours to earn $260.

Confidential 17

2) A car travels east at a speed of 50 mph and a motorcycle travels west at a speed of 55 mph. If they start at the same time and place, how long will it take them to be 315 miles apart?

First let us draw a figure.

let they traveled for x hours.

50 mph55 mph

315 miles

Confidential 18

Distance traveled by car = rate × time Distance traveled by car = 50 × x = 50x

Distance traveled by motorcycle = rate × time Distance traveled by motorcycle = 55 × x = 55x Total distance= 315 50x + 55x =315 105x = 315 (divide both sides by 105) x = 3 hours

Confidential 19

3) The population of Alaska is 603,617 with 253,922 of those people living in Anchorage. The area of Alaska is 570,374 square miles. The area of Anchorage is 1,697.6 square miles.

a. Find the population density of Alaska

b. Find the population density of Anchorage

a.1.06 people per square mile

b. 149.58 people per square mile

Confidential 20

Let Us Review

A rate is a ratio that is used to compare different kinds of quantities.

A unit rate describes how many units of the first type of quantity corresponds to one unit of the second type of quantity.

A unit price is a rate comparing the price of an item to its unit of measure.

To find the unit price divide the total cost by the number of items bought.

Confidential 21

Let Us Review

Rate = Distance/time– To find rate divide distance by time

Time = Distance/rate– To find time divide distance by rate

Confidential 22

You had a Great Lesson Today!

Be sure to keep practicing