Once again, as in previous lessons, you may find that students
have varying abilities to perform the mathematical operations.
You may want to put them in mixed-ability groups to complete
the exercises on this page and then go back later to provide
more practice for beginning-level students in changing percentages
to decimals, multiplication, and multiplication with decimals.
If beginning-level students at least grasp the general concepts,
reassure them that they will find that the lender will perform
the calculations for them at their loan interview.Go over
the following steps
1. Explain to students why it is important to know how
to find the percentage of a known amount.
2. Work several problems on the blackboard or on chart
paper before having students complete the exercise. First,
change the percentage to a decimal. Then multiply the known
amount by the decimal. Don’t forget to move the decimal
in the answer
two places to the left.
3. Have students think of other situations in which they
might use this skill. Some examples might be finding the
price of a discounted item (e.g.,
a $20 dress that is 40 percent off), reducing the size of
a recipe, or calculating how much you have to put down on
a car you purchase.
4. Have the students complete the practice exercises by
hand.
5. Give students a calculator and have them work the same
problems or
provide additional examples.
In the Home Mortgage Qualifying Worksheet,
you will be asked to find a given percentage of certain
amounts of money. First, you will be asked to figure out
28 percent of your gross monthly income. That is how much
a lender will usually allow you to spend on housing each
month.
Then you will be asked to figure out 36
percent of your gross monthly income. That is how much total
monthly debt, including mortgage payments and other debts,
a lender will allow you to have. By filling in these numbers
on the worksheet you can find out whether you can qualify
for the house you want.
This kind of calculation is called finding
a percentage of a known amount. What you are really
doing is looking for one missing piece of information. In
working with money it is usually easiest to use what is
called the decimal method to get the answer.
First you change the percentage to a decimal. For example,
28 percent would be changed to .28. (Go back to Lesson 1
if you don't remember how to do this.) Next, multiply the
percentage times the whole. For example, multiply $3,000
by .28:
$3,000
x .28
----------
24000
6000
----------
84000. Move the decimal point two places to the left.
$840.00
You should practice working some problems
by hand, but you can also use a calculator to get the answers
more quickly.
To find 28% of a $1,200 monthly income:
1. Change 28% to a decimal by moving the
decimal two numbers to the left: 28% = .28
2. Multiply:
$1,200
x .28
----------
33600
Move the decimal two places to the left,
$336.00.
To find 36% of a $1,200 monthly income:
1. Change 36% to a decimal by moving the
decimal two numbers to the left: 36% = .36
