1. Finding Percents of
numbers
Using the Is over Of technique
in conjunction with drawing
percent bars

2. What do you think is the answer??
• Find 25% of 20
• Let’s draw a picture.
? 25%
20 100%

3. Can you solve this as a proportion?
• Find 25% of 20
• What would the proportion look like?
x 25
? 25%
20 1 00
X=5
20 100%

4. We can do this Mathematically by
using a special proportion...just
find the following...
The Percent – it is the easiest to find.
Just look for the % sign!
The “Of” number - it is always just
behind the word of.
The “Is” number - it may or may not be
near the “is” word. If you find the
other two then what is left is the “is”!

5. Finding is, of or a Percent
is %
Use the proportion…
of 100
Find the missing number by drawing a bar and using the
proportion.
a) 15% of 900 is what?
x 15 ? 15%
900 1 00
x = 135
900 100

6. Finding is, of or a Percent
is %
of 100
Find the missing number by drawing a bar and using the
proportion.
b) What % of 84 is 63?
63 %
84 1 00
63 x%
X = 75% 84 100

7. Finding is, of or a Percent
is %
of 100
Find the missing number by drawing a bar and
using the proportion.
c) 35% of what # is 7?
7 35%
7 35
x 1 00
? 100
X = 20

8. Finding is, of or a Percent
is %
of 100
Find the missing number by drawing a bar
and using the proportion.
d) 2.5% of 120 is what?
? 2.5%
x 2.5
1 20 1 00
x=3 120 100

9. Finding is, of or a Percent
is %
of 100
Find the missing number by drawing a bar
and using the proportion.
60% of 600 is what number?
x 60
600 1 00 x 60%
x = 360 600 100

10. Homework: P. 322 #2-26 evens
You MUST show the proportion and the
work you do to get the answer.