1. Factors and Simplest Forms
Section 4.2
Factors and
Simplest Forms

2. Factors
Any number that divides a number evenly (with a remainder of zero).
Find the factors of 18.
Find the factors of 7.

3. Prime Number
A natural number (positive whole numbers) greater than one, whose only factors are 1 and itself.
Circle the Prime Numbers.

4. Composite Number
A natural number (positive whole numbers) greater than one, that is not prime.
Circle the Composite Numbers.

5. 1
The natural number one is neither prime nor composite

6. Prime Factorization
A composite number that is written as a product of prime numbers.
144 = 2 * 2 * 2 * 2 * 3 * 3

7. Factor Tree
A method to find the prime factorization is called the factor tree.

8. Example
Fill in the boxes, then determine the prime factorization

9. Example

10. Divisibility Test A whole number is divisible by
2 if the last digit is 0, 2, 4, 6, or 8
3 if the sum of the digits is divisible by 3
5 if the last two digits is 0 or 5

11. Example
Find the Prime Factorization of 42 78 99

12. Equivalent Fractions
Fractions with the same portion of a whole.

13. Simplest Form
A fraction is written in simplest form or lowest from when the numerator and the denominator have no common factors other than one.

14. Example
Write the fraction in simplest form.

15. Example
Write the fraction in simplest form.

16. Example
Write the fraction in simplest form.

17. Example
Write the fraction in simplest form.

18. Example
Write the fraction in simplest form.

19. Example
Write the fraction in simplest form.

20. Example
Write the fraction in simplest form.

21. Equivalent Fractions
To determine if two fractions are equivalent use a method called crossed multiply.

22. Example
Determine if these fractions are equal

23. Example
Determine if these fractions are equal