## Sunday, January 16, 2011

### Bennette's Final Percent Post

PERCENT - means out of 100
-can be expressed as fraction (n/100) and as a decimal (o.1)

4.1 Representing Percents:
- One completely shaded grid represents 100%
- If you need to shade more than 100, you can use another grid.
- To show a fractional percent between 0% and 1%, shade part of one square
- To represent a fractional percent more than 1%, shade squares from a hundred grid to show the whole number and part of one square from the grid to show the fraction.

EXAMPLE:

4.2 Fractions,Decimals, and Percents
-
Fractions, decimals, and percents can be used to show numbers in different situations.
-Percents can be written as fractions and as decimals.

EXAMPLE:

4.3 Percent of a Number
-
We can use mental math techniques such as halving, doubling, and dividing by 10 to find the percents of some numbers.
- To calculate the percent of a number, write the percent as a decimal and then multiply by the number.

EXAMPLE:
12 1/2 % of 50 = 0.275 x 50
= 13.75

4.4 Combining Percents
-
Percents can be put together by adding to solve problems.
eg. 5% + 7% = 12% ( We always use 12% as tax in our case)
- You can add the combined percent amount to the original number.
eg. 15 % of 100 = 0.15 x 100 = 15
100 + 15 = 115
- You can multiply the original number by a single percent greater than 100.
eg. 155% of 100 = 1.15 x 100
= 115
- Percents of percents can be used to figure out amounts that result from consecutive percent increases or decreases

PERCENT REVIEW VIDEO:

My scribe post: http://spmath81710.blogspot.com/2010/11/pythagoras-textbook-questions-and.html

(I don't have the percent post because I blogged early when our percent chapter started, so I used the last blog I made which is Pythagoras)

http://www.mathgoodies.com/lessons/vol4/meaning_percent.html
http://www.mathsisfun.com/decimal-fraction-percentage.html
http://www.mathsisfun.com/percentage.html

Here are some math gaming sites you may want to check out:

http://www.mathsisfun.com/games/index.html
http://www.mathplayground.com/games.html
http://www.mathgoodies.com/lessons/vol4/challenge_vol4.html

Here are some percent video you may want to watch: