Welcome to Welcome to Math112Math112

Class #6Class #610-8-1410-8-14

Welcome to Welcome to Math112Math112

Class #6Class #610-8-1410-8-14

Don’t turn in HW yet! Review this week’s Don’t turn in HW yet! Review this week’s HW AND last week’s HW AND the sample HW AND last week’s HW AND the sample test. We will go over any questions you test. We will go over any questions you

have for 15 minutes. Test #2 will begin at have for 15 minutes. Test #2 will begin at 7:15. 7:15.

Tonight’s Agenda•Warmup•Go over questions from sample

test or any homework assigned•Test #2•Fractions, Decimals, & Percents

Three small rules for living a happy life:

1. Start each day with a grateful heart. 2. Focus on the positive aspects of every person you encounter. 3. End each day with a grateful heart. Lucy MacDonald

Answers to HW Worksheet p. 24 “Why did the ant run across the cracker box?”

Answers to HW Worksheet p. 62 “Can you build

this?”

Test #2Test #2Test #2Test #2

When you finish, take a break.When you finish, take a break.

Class will begin at __________.Class will begin at __________.

Rounding NumbersRounding NumbersRounding NumbersRounding Numbers

Objective - To round decimals to a specified place value.

Rounding NumbersLook at the digit to the right of where you are rounding.

1. If the digit is 4 or less, round down.2. If the digit is 5 or more, round up.

1) 3) 6728 12,376

Round to the nearest hundred.

5) 35,632

2) 4)4082 6,148 6) 11,962

6700

4100

12,400

6,100

35,600

12,000

1) 3) 36.378 0.432

Round to the nearest hundredth.

5) 0.4852

1) 2) Tens Thousandths

Round 479.7245 to the given place value.

3) Ones

2) 4)4.196 179.995 6)6.0073

36.38

4.20

0.43

180.00

0.49

6.01

480 479.725 480479.7245 479.7245 479.7245

Fractions, Fractions, Decimals, and Decimals, and

PercentsPercents

Fractions, Fractions, Decimals, and Decimals, and

PercentsPercents

Ordering DecimalsPut the following decimals in order

of size, starting with the one with the least value:

0.125, 0.4, 0.62, 1.05, 0.05

Ordering FractionsPut the following fractions in order

of size, starting with the one with the least value:

3 9 3 7 3, , , ,

4 16 16 8 8

Which number is larger?

1. 40% or ¼2. 0.7 or 3/53. 33% or 0.4

Handout

Decimal to percentDecimal to percentandand

Percent to decimalPercent to decimal

Decimal to percentDecimal to percentandand

Percent to decimalPercent to decimal

Decimal Percent

43% 0.43

43100

34% 0.34

0.05 5%

Writing Decimals as PercentsD P Right P D Left

Fraction to percentFraction to percentandand

Percent to fractionPercent to fraction

Fraction to percentFraction to percentandand

Percent to fractionPercent to fraction

Fraction Decimal Percent

38

means 3 8

0 3

24 6 0

7

56 4 0

5

40 0

0.375

0.375 37.5%

3.000 8

Writing Fractions as Percents

Write each fraction as a percent.

1) 1

2

2) 3

5

3) 6

20

4) 28

40

5) 9

25

6) 24

60

50

100

50%

60

100

60%

30

100

30%

7

10 70

100

70%

36

100 36%

2

5 40

100

40%

5050

2020

55

44 10

10

44

1212 20

20

Write each percent as a fraction.

1)

2) 82%

3) 3%

50%

Decimal to fractionDecimal to fractionDecimal to fractionDecimal to fraction

Converting Decimals to Fractions

Decimal Fraction

2.3

0.14

2.04

Just read it correctly!

Two and three-tenths

Fourteen hundredths

Two and four- hundredths

3210

14100

22

750

42100

44

1225

Fraction Decimal Percent

25 0.4 40%

8100 0.08 8%

71000 0.007 0.7%

710 0.7 70%

1 3

10 1.3 130%

2

25

Complete the table.

Fraction Decimal Percent

45 0.8 80%

16100 0.16 16%

91000 0.009 0.9%

310 0.3 30%

2 7

10 2.7 270%

4

25

Complete the table.

Percent change = Percent change =

Difference between the two valuesDifference between the two values x x 100%100%

The starting valueThe starting value

Percent change = Percent change =

Difference between the two valuesDifference between the two values x x 100%100%

The starting valueThe starting value

Example 1The price of a parking ticket in LA

has increased from $50 to $75. What is the percent increase?

Example 2The price of a pair of pants has

decreased from $60 to $40. What is the percent decrease?

Real world use of Real world use of percentspercents

Real world use of Real world use of percentspercents

Discount, Commission, Profit, Discount, Commission, Profit, and Interestand Interest

DiscountOriginal Price - Discount = New Price

A pair of shoes that was originally $80 is on sale for 40% off. Find the amount of the discount and

the new price.Discount New Price

40% of $800.40 ($80)

$32

$80 (40% of $80)$80 0.40 $80

$80 $32 $48

(100% 40%) of $8060% of $800.60 $80 $48

Subtractsthe

Money

Subtracts the

Percents

Finding the Percent Mark-up

A baseball glove that was purchased wholesale for $60 is now selling retail for $72. Find the

percent mark-up.

Percent Mark-up Percent Change

From $60 to $72

12

60

= 0.2 0

%Orig. Amt.

%

% Mark-up20%

THE TRIANGLE

IS A SYMBOL FOR THE WORD

“CHANGE”

Mark earns a 12% commission on all the cars hesells. He expected his sales in July to be $35,000, What commission was he expecting?Expected

12% of $35,0000.12 (35,000)

$4200

Mark earns a 12% commission on all the cars he sells. He was only able to sell $28,000. How muchcommission did he earn?

Actual

12% of $28,000

0.12 (28,000)$3360

Mark earns a 12% commission on all the cars hesells. He expected his sales in July to be $35,000,but he was only able to sell $28,000. How much

less were his commissions than expected?Expected Actual

12% of $35,0000.12 (35,000)

$4200

12% of $28,0000.12 (28,000)

$3360$4200 $3360 $840 less than

expected

Objective - To solve problems involving simple interest.

If someone borrows money, what factors influencehow much is paid back?

Principal -How much was borrowed.

Time - How long it was borrowed for.(in years)

Rate -(annual % rate)

What interest was charged.

Amount to Payback =Principal + Interest

Interest =Principal Rate Time

I P r t

Joe borrows $200 from the bank at 6% simpleinterest for 3 years. What interest does he owe,

and what is his total balance (amount to payback)?

Interest Balance

I P r t I (200)(0.06)(3)

I 36

Interest owed $36

Balance =P + I

Balance =200 + 36

Balance = 236

Balance = $236

P 200r 6% 0.06t 3

Juan invests $5000 in bonds for 6 months at anannual interest rate of 7%. How much interest

did he earn, and what is the balance in his account?

Interest Balance

I P r t I (5000)(0.07)(0.5)

I 175

Interest owed $175

Balance =P + I

Balance =5000+175

Balance = 5175

Balance = $5175

P 5000r 7% 0.07t 6 months 0.5 years

Homework #6 (worksheets)

Worksheet:“Fractions, Decimals, and Percents (Revisited)”

Worksheets pp. 120 - 125