If 'b' divides 'a' leaving zero remainder then 'b' is called a factor or divisor of a, and a is called multiple of b.

Example:
In the problem 5|25,
1. 5 is a factor of 25.
2. 5 is a divisor of 25.
3. 25 is a multiple of 5.

Example:
In the problem 9 x 7 = 63,
1. 9 is a factor of 63.
2. 7 is a factor of 63.
3. 63 is a multiple of both 9 and 7.

Example:
Write all the factor of 28.
28 = {1,2,4,7,14,28}
Write down all the factor of 6.
6 = {1,2,3,6}
From above examples we can observe that,
1. 1 is a least factor of every natural number.
2. Every natural number is the factor of itself and it is the greatest.

Directions: Choose the correct answer. Also write at least five examples of factors and multiples of your own.