Factors

1. The numbers that are multiplied to find a product are called its factors.
2. 1 is a factor of every number. It is also the smallest factor of a number.
3.  Every number is a factor of itself. It is also the greatest factor of that number.
4. The factor of a number is less than or equal to the number.
5. Every number has at least two factors -1 and itself.

Rules of Divisibility:

A number is divisible by

• 2 –If the last digit is 0,2,4,6,8
• 3 –If the sum of the digits is divisible by 3
• 4 –If the number formed by the last two digits is divisible by 4 or ends with
• 00
• 5- If the last digit is 0,5
• 6- if the number is divisible by both 2 and3
• 9- If the sum of the digits is divisible by 9
• 10- If the last digit is 0

The prime factorization of 63 is __________.
✅ Answer: 3 × 3 × 7

3. Multiple Choice

Which of the following has more than two factors?
a) 2
b) 11
c) 9
d) 7

✅ Answer: c) 9
 Explanation: 9 is composite (factors: 1, 3, 9)

4. Multiple Choice

Which of the following is not a prime number?
a) 17
b) 23
c) 51
d) 47

✅ Answer: c) 51
 Explanation: 51 = 3 × 17 → composite

5. Fill in the Blank

The number 1 is __________ prime nor composite.
✅ Answer: neither

1. The prime factorization of 36 is __________.
✅ Answer: 2 × 2 × 3 × 3

2. The prime factorization of 100 is __________.
✅ Answer: 2 × 2 × 5 × 5

3. 2 × 2 × 2 × 3 is the prime factorization of __________.
✅ Answer: 24

4. The number 45 is a __________ number (prime/composite).
✅ Answer: composite
 Explanation: Factors: 1, 3, 5, 9, 15, 45

5. Fill in the missing factor: 3 × 3 × ___ = 81
✅ Answer: 3
 Explanation: 3 × 3 × 3 × 3 = 81