# Determining common factors

### Determining common factors

Ever taken apart a puzzle? Well, just like a puzzle, numbers can be taken apart. Factors are like the parts of a number that are left after you have taken apart the number. When two or more numbers have the same factor, this is called a common factor. In this section, we will be determining the factors of whole numbers, including the common factors of pairs of numbers. We will be using the divisibility rules learned in previous section.
Basic concepts: Place value,

#### Lessons

• Introduction
a)
What is a factor?

• 1.
What are the factors of 20?

• 2.
What are the common factors of each pair of numbers?
a)
12, 16

b)
17, 19

• 3.
Margaret has 45 balloons and 60 lollipops. She wants to put together goody bags for her birthday party that have the same numbers of balloons and lollipops in each bag. What is the greatest number of goody bags that she can put together?

• 4.
Michelle has 12 red flowers, 28 blue flowers, and 36 yellow flowers. She wants to make bouquets with the same number of each color of flower in each bouquet. What is the greatest number of bouquets she can make?