Working with Percents
- Percents can be converted into multipliers by changing them into their decimal form to easily calculate a percentage of a number.
- To solve for an unknown in percentage problems, replace the unknown with a variable and translate the problem into an equation using the percent as a multiplier.
- When finding what percent one number is of another, set up an equation with the unknown percent as a variable, solve, and remember to convert the decimal back to a percentage.
- For percentages that are easily represented as fractions (e.g., 50%, 25%), it can be simpler to convert the percent to a fraction to solve the problem.
- Practice problems are provided to apply these strategies and reinforce understanding.
Solutions to the Practice Problems:
1) What is 60% of 60
Let's translate this into a simple equation.
What --> "x" or what we are trying to find.
is --> "="
60% --> 60/100 or .6
of --> " *"
x = .6 * 60
x = 36
So all we did was multiply 0.6*60 and we get 36 as our answer.
2) 52 is 40% of what number?
is --> "="
40% --. 40/100 or .4
of --> " * "
what number --> x
52 = .4 * x
We divide both sides by 0.4 and we get X = 52/0.4 = 130
Let's do a check and make sure we did everything right.
3) 18 is what percent of 45?
Before we do anything math let's do a ball park. We know that half of 45 is 22.5 So without doing any math/computation we know that 50% of 45 is 22.5 so 18 is going to be less than 50>#/p###
is --> " ="
what percent --> x/100
of --> "*"
18 = (x/100) * 45
18/45 = x/100
.4 = x/100
40 = x
So 18 is 40% of 45.
Notice we can simply divide 18 by 45 to get .4
.4 is 40% in decimal form.
4) What is 50% of 128? [64]
This one you're just dividing 128 by 2.
x = .5 * 128 or 128/2
128/2 = 64
