## Wednesday, December 18, 2013

### Amanda's Percent Post

A percent is an equivalent fraction out of 100. A fraction is a percent or can be converted to a percent. To get the percent from a fraction you need to divide the numerator by the denominator, this will give you a decimal. You then multiply the decimal by 100. That number is going to be your percent.

Ex. 4/5
4/5 = 0.8
0.8 x 100 = 80%
80 = 80%

100% means everything! 100/100 or 37/37
For 100%, say your fraction was 100/100. To find 100% you divide 100 by 1. Since you're only dividing 100 by 1 it's still going to be 100. It's still going to be the same. This works with all fractions that have the same numerator and denominator.
Ex:100% of 60=?
60/1=60
60=60

50% means half, 1/2 or 50/100.
To find 50% you must divide your number by 2. That gives you half of your number which is 50%
Ex:50% of 60=?
60/2=30
30=30

25% means 1/4, 25/100 or divided by 4.
To find 25% you must divide your number by 4. The number you get is 1/4 of the number you started with.
Ex:25% of 60=?
60/4=15
15-15

10% means 1/10, 10/100 or divided by 10.
To find 10% you must divide your number by 10. This gives you a number that is 1/10. This number is 10% of the number you started with.
Ex:10% of 60=?
60/10=6
6=6

1% means 1/100 or divided by 100.
To find 1% you must divide your number by 100. This give you a number that's 1/100 or 1%.
Ex:1% of 60=?
60/100=0.6
0.6=0.6

a) 180%

b) 0.6%

c) 12 3/4%

Converting Fractions to Decimals and Percents: 88/50
Numerator divide by the Denominator
88 divide by 50 = 1.76
1.76 x 100 = 176%

Converting Decimals to Percents and Fractions: 0.0064
0.0064 x 100 = 0.64 or 0.64%
64/10000 divide by 16/16 = 4/625

Converting Percents to Decimals and Fractions: 750%
750 divide 100 = 7.5
750/100 = 7.5 or 7 1/2

Show How You Know:

20% of 60: 20÷100= 0.2
0.2 x 60=12
20% of 6 = 12

0.1% of 40:0.1÷100=0.001
0.001 x 40=0.04
0.1% of 40 is 0.4

250% of 400:250÷100=2.52.5 x 400=1000
250% of 400 is 1000

Question #3 on pg 148:

a) 15 ÷ 100 = 0.15       b) 10 ÷ 100 = 0.1          c) 25 ÷ 100 = 0.25
0.15 x 200 = 30            0.1 x 230 = 23              0.25 x 200 = 50
30 + 200 = 230             23 + 230 = 253            50 + 200 = 250

Kyle is incorrect.

Discount - what you save
Sale Price - what you pay
Total Price - what you pay altogether with tax.
( Discount - Original Price = Sale Price)     (Sale Price + Tax = Total Price)

Show How You Know pg 148
Which is a better buy? What is the final price?
Plate Collection \$ 68.00
Store A: 50% off one day only
68 ÷ 2 = \$34

Store B: 25% off one day followed by 25% off the reduced price the second day.
25 ÷ 100 = 0.25               \$51 x 0.25 = \$12.75
0.25 x 68 = \$17               \$51 - \$ 12.75 = \$38.25
\$68 - \$17 = \$51

Store A has a better deal because it is less than Store B after the discount.