## Tuesday, February 1, 2011

### Robin's Final Percent Post

~ A percent means out of 100 and it's another name for hundreths which can be represented as a decimal or fraction
~Ex. 65% means 65 out of 100 or 65/100 or 0.65

4.1 Representing Percents

Key Ideas
To represent a percent you can use 100 grid charts. One shaded grid that has all the squares shaded in represents 100%. To show a percent that is larger than 100% you shade in more than one grid. To represent a percent between 0% and 1% you shade in a part of one square.

Fractional Percent - A percent that includes a portion of a percent.
Ex. 1/2%, 0.42%, 73/8%, 125 3/4%, 4.5%

4.2 Fractions, Decimals, & Percents

Key Ideas :
Fractions, decimals, and percents can be used to represent numbers in various situations.
Percents can be written as fraction as decimals.
Ex. 1/2%=0.5% 0.5%=0.5/100 =0.005
150%=150/100
=1.5 or 11/2
423/4%=42.75% 42.75%=42.75/100 =0.4275

4.3 Percent of a Number

Key Ideas :
You can use mental math strageties such as halving, doubling, and dividing by ten 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.
Ex.121/2% of 50 = 0.125 x 50 = 6.25
121/2%=12.5 = 0.125

4.4 Combining Percents

Key Ideas :
Percents can be combined by adding to solve problems. 5% + 7% = 12%
To calculate the increase in a number,
~You can add the combined percent amount to the original number: 12% of 100 =0.12 x 100 = 12 100+12=120
~You can multiply the original number by a single percent greater than 100
Percents of percents can be used to determine amounts that result from consecutive percent increases or decreases.