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