## Wednesday, December 18, 2013

### Ainsley's Percent Post

A percent is an equivalent fraction of 100. In other words, fractions are turned into decimals and those decimals are turned into percentages!

100 percent means everything 100/100 or 10/10.
To find 100 percent, you have to divide the denominator by 1.
For example: If you had 40 apples and you wanted to find 100% of those 40 apples, you just have to divide 40 by 1. That still give you 40 which means 40 is 100%. You do that because 40 is the denominator or in other words, the whole or whole amount.

50 percent means half, 1/2, or 50/100.
To find 50 percent, you have to divide the denominator by 2.
You have to divide the denominator by 2 because it is half. For example, if you wanted to find 50% of those 40 apples, you divide 40 by 2. That gives you 20 which means 50% of 40 is 20.

25 percent means 25/100 or 1/4.
To find this percent, you have to divide the denominator by 4.
For example: If you had 100 and divided it by 4, that would equally give you 4 x 25. In our case, we have 40 apples. That means you have to divide 40 by 4 instead of 100 by 4. That gives and leaves you with 10.
10 x 4 = 40

10 percent means 10/100 or 1/10.
To find 10 percent, you have to divide the denominator by 10.
You have to do that because for example, the whole percent is 100. If you wanted to find 10% of 100, you would just have to divide it by 10. In this case, you have 40 apples and that means your "whole amount" is 40. Now if you divide 40 by 10, you get 4. To check if it's right, you can do the opposite operation which is multiply. (4 x 10=40)

1 percent means 1/100.
To find this percent (1 percent), you have to divide by 100.
Example: If we divided 100 by 1, we would get 1. In our case, we have 40 apples instead of 100 so it's different. We would have to divide 40 by 100. Once we do that, we get 0.4 or 0.40 (same thing). Now to show that that makes sense, we can multiply by 100 (opposite) and get 40 as our answer.

Representing Percents:

180:
12 3/4 %
0.6%
OR

Converting Percents, Fractions, and Decimals.

Converting fractions to decimals and percents:
3/40: To do this you have to divide the numerator by the denominator. Then, you have to multiply that decimal by 100 to get your percent. 3 divided by 40= 0.075. 0.075 x 100= 7.5%

Converting decimals to percents and fractions:
5.98: To do this, you have to multiply by 100. To find the fraction, you may count the amount of digits or 0's which in this case is 3 but you replace the first digit or the ones with a 1. 5.98 x 100= 598%. 5 98/100.

Converting percents to decimals and fractions:
750%: To do this, you have to divide the percent by 100. That is because a percent is always equivalent to 100 so you have to do the opposite operation. 750 divided by 100 = 7.5. In this case, it would be 7 1/2 since 50 is half of 100.

Show How You Know:
20% of 60:
20 ÷ 100= 0.20
0.20 x 60= 12
20% of 60 = 12

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

250% of 400:
250 ÷ 100= 2.5
2.5 x 400= 1000
250% of 400= 1000

5- Combining Percents
Question 3 - Page 148. Example #- 200

15 ÷ 100 = 0.15
0.15 x 200 = 30
200 + 30= 230

10 ÷ 100= 0.10
0.10 x 230 = 23
230 + 23 = 253

25 ÷ 100 = 0.25
0.25 x 200 = 50
200 + 50 = 250

Kyle is not correct because 253 > 250.

Show You Know - Page 148
Example # - 200
Store A- 50% off one day only.
Store B- 25% one day + 25% off the reduced price the second day.

50 ÷ 100 = 0.50
0.50 x 200 = 100
200 - 100 = 100

25 ÷ 100 = 0.25
0.25 x 200 = 50
200 - 50 = 150

25 ÷ 100 = 0.25
0.25 x 150 = 37.50
150 - 37.50 = \$112.50

Store A has the better buy or price because at the end, the sale price would be \$100. At Store B, you would have to pay \$12.50 more than Store A.