Classroom Observation Tool

1. FINDING THE
PERCENTAGE IN A
GIVEN PROBLEM

2. DRILL

4. What’s your
target score in a
20 item quiz? Is it
75%, 80%, 90%
or 100%?

5. • Jouriz, a girl from a farm village is a diligent
and studious pupil. She goes to school every
day and does her work well. She never skip
studying her lesson every night. When she
took their 50-item quarter examination she
got 96% of it correctly. What is her score?

6. DEFINITION
• PERCENTAGE- is the number
or the amount that represents
a part of the whole.
• - after the word “is”
Formula
• Percentage = Base x Rate
Rate = Percentage
Base
• BASE - is the whole amount or the
entire amount
• - usually after the word “of”
Formula
• Base = Percentage
Rate
RATE- is the number compared to
100
- Usually has the percent % symbol

7. Techan’s Triangle

8. To find the percentage:
What is 96% of 50?
 Change the rate to decimal numbers
96% = move 2 decimal places to the left (0.96)
 And solve using the formula
 P = Base x rate
= 50 x 0.96
P = 48 her score

9. Example
1. What is 80%
of 200?
P = B X R
= 200 X ( 0.8)
P = 160
2. Give 30 % of
150?
P = B x R
= 150 x (0.3)
P = 45

10. Practice Task

11. • 3. 6% of 200 = N
P = B x R
= 200 x 0.06
= 12 (e)
4. 12% of 400
P = B x R
= 400 x 0.12
= 48 ( b)
5. 25 % of 240
P = B x R
= 240 x 0.25
= 60 (a)
Solution:
1. 75% of 100
P = B x R
= 100 x 0.75
= 75 ©
2. 60% of 90
P = B x R
= 90 x 0.6
= 54 ( d)

12. Direction: Complete the table by filling up the
percentage.
Base Rate Percentage
1. 40 12%
2. 175 80%
3. 40 75%
4. 300 40%
5. 60 25%

13. Generalization
To find the percentage use the formula: Percentage
= Rate x Base (P = R x B)
Express the rate as a decimal by moving the
decimals by moving the decimal point twice from
the left. Multiply the number following the steps in
multiplication.

14. EVALUATION
• Direction: Find the Percentage on the following
items:
• 1. What is 30 % of 150?
• 2. What is 50% of 100?
• 3. 75% of 30 is what number?
• 4. Give 25% of 500
• 5. 10% of 60 is N
•

15. V. ASSIGNMENT
Find the value of N
a. 10 % of 45 = n
b. 12% of 89 =n
c. 25% of 500?

16. THANK YOU!!!