1. Lesson Plan in Mathematics Five
I. Objectives:
At the end of the lesson, the pupils are expected to:
1. find the prime factors of a number,
2. write the prime factors of a given number correctly and
3. participate actively in the discussion/activities
II. Skill: Finding the prime factors of a number
Mathematical Concept:
The prime factors of a number are the multiplication expression using prime numbers as its
factors. The prime factors of a number can be determined using a factor tree or continuous division by
primes.
Reference: MATH 5 BEC-PELC I.A 1.4
Realistic Math 6, p.78
Materials: chart, flash cards, activity sheets
Values: Alertness, active participation
III. Learning Experiences
A. Preparatory Activities
1. Drill ( Giving the factors of a given number )
Strategy: Active Participation (Popcorn)
Materials: flash cards
Mechanics: 48 24 28 32 16
a. Flash the cards with numbers. 56 36 45 54 63
b. The pupils will stand immediately and give the factors orally.
Valuing: ( How did you answer the drill exercises?)
2. Review (Identifying prime and composite number)
Strategy: Active Participation (Thumbs up or thumbs down)
Materials: flash cards
Mechanics:
a. Tell whether the following numerals are prime or composite.
b. If the numeral is a prime, show the thumbs up and thumbs down if it is composite.
17 3 5 21 19 7 2 6 25 91

2. 3. Motivation
Give number combinations that will give the product of 18.
Expected Answer
X 2 X 9 = 18
X 3 X 6 = 18
X 1 X 18 = 18
B. Developmental Activities
1. Presentation
Strategy 1: Making an Organized List
Group Activity
a. Use the prime numbers listed on the board ( 2, 3, 5, 7 ) as factors.
b. Find a combination of prime numbers, multiply them and record the number sentence.
c. Write all the findings in a table or chart.
Expected outputs
Number Sentence Product
2x3 6
2x5 10
2x7 14
3x5 15
3x7 21
5x7 35
2x3x5 30
2x3x7 42
3x5x7 105
2x3x5x7 210
Analysis and Discussion:
a. Ask, “What can you say about the factors of these products? ( They are all prime numbers. )
b. Elicit from the pupils that those are the prime factors of the numbers.
c. Reverse the situation. Give the product and the pupils give the prime factors.
d. Ask, “Given number is 36, What are its factors?
e. How can we write 36 as a product of its prime factors?
f. Let the pupils list the factors of 36.
g. Let them list the prime factors of 36.
36 = 6 x 6
2x3x2x3
36 = 2 x 2 x 3 x 3

3. Strategy 2: Factor Tree
a. Give each group two-digit numbers and a factor tree printed on a cartolina.
b. Have the pupils determine two factors of the given number. Write them on the first two
boxes of the factor tree.
c. Find the two factors of the first two factors. Write them on the next two boxes.
d. Continue extracting factors of the number until the last box contains prime numbers.
48 45
8 6 9 5
4 2 2 3 3 3
Prime factors of 45 = 3 x 3 x 5
2 2
So, the prime factors of 48 = 2 x 2 x 2 x 2 x 3
Strategy3: Continuous Division by primes
2 36 2 54
Prime Factors of 36 Prime factors of 54
2 18 36 = 2 x 2 x 2 x 3 3 27 54 = 2 x 3 x 3 x 3
2 9 3 9
3 3 3 3
1 1
2. Fixing Skills
Find the prime factors of these numbers using the two methods.
Slow learners: Average learners: Fast learners:
a. 16 a. 36 a. 64
b. 24 b. 48 b. 72
c. 12 c. 50 c. 120
d. 18 d. 54 d. 210

4. 3. Generalization
How do you find the prime factors of a number?
We can find the prime factors of a number through:
a. factor tree method
b. Continuous Division by Primes
C. Application
1. How would you begin to find the prime factors of 246?
2. Give the prime factor of 1,000.
IV. Evaluation
Give the prime factors of the following number using any method.
1. 78
2. 72
3. 80
4. 150
V. Assignment
Write the prime factors of the following numbers.
1. 84 5. 93
2. 240 6. 110
3. 60 7. 91
4. 42 8. 50