Math Review: Fundamentals of Math
Making Conversions | Keywords in Word Problems | Taking Percentages | Scientific Notation | Integers | Fractions | Decimals (including percents) | Ratios and Proportions | Units of Measurement and Conversions | Miscellaneous Problems
Percentages
The formula below is useful when working problems involving percentages.
Percent ´(of) = (is)
in decimal form
what we are taking
the result after the percentage
a percentage of
has been taken
EX: What percent of 40 is 24?
P ´ 40= 24
P = 0.6 Þ 60%
Percentages can also be found using the proportion below.
Percent( is)______________________________ _______ _________________
_______
100(of )
ex. 20% of what number is 34?
cross multiply
20x = 3400 divide both sides by 20
x = 170
©2002, Last Updated:
June 15, 2007
El Centro College
Communications, Mathematics, Developmental Studies, and Teacher Preparation Division