Title: Multiples%20and%20Factors
1Multiples and Factors
2Multiples
- A multiple is formed by multiplying a given
number by the counting numbers. - The counting numbers are 1, 2, 3, 4, 5, 6, etc.
3Example List the multiples of 4
- 4 x 1 4
- 4 x 2 8
- 4 x 3 12
- 4 x 4 16
- 4 x 5 20
- 4 x 6 24
So, the multiples of 4 are 4, 8, 12, 16, 20, 24,
28, etc.
Counting Numbers
4What are the first five multiples of 13?
13 x 1 13 13 x 2 26 13 x 3 39 13 x 4 52 13
x 5 65
13, 26, 39, 52, 65
5Find the Missing Multiples
24
30
- 6, 12, 18, ____, ____
- ___, 6, 9, 12, ____, ____, 21
- ___, 24, 36, 48, 60, ____
15
18
3
72
12
6Factors
- Factors are the numbers you multiply together to
get a product. - For example, the product 24 has several factors.
- 24 1 x 24
- 24 2 x 12
- 24 3 x 8
- 24 4 x 6
- SO, the factors are 1, 2, 3, 4, 6, 8, 12, 24
7Finding Factors
- Start with 1 x the number.
- Try 2, 3, 4, etc.
- When you repeat your factors, cross out the
repeat - youre done at this point. - If you get doubles (such as 4 x 4), then youre
done. Repeats or doubles let you know youre
done.
8What are the factors of 16?
1 x 16
2 x 8
3 x ??
3 is not a factor, so cross it out
4 x 4
doubles done
The factors of 16 are 1,2,4,8,16
9What are the factors of 18?
1 x 18
The factors are 1,2,3,6,9,18
2 x 9
3 x 6
4 x ??
5 x ??
6 x 3
Repeat! Cross it out! Were done!
10What are the factors of 7?
The only factors of 7 are 1,7
1 x 7
2 x ??
3 x ??
4 x ??
5 x ??
6 x ??
7 x 1
This works, but it is a repeat. We are done.
11Prime and Composite Numbers
- Prime numbers are
- numbers that only have
- two factors one, and the
- number itself.
- EXAMPLES
- 3, 5, 7, 11, 31
- Composite numbers
- have more than two
- factors.
- EXAMPLES
- 6, 18, 30, 100
12Homework Time