1. Math 5 Simplifying Fractions
Instructor: Mrs. Tew Turner

2. In this lesson we will learn how to recognize & write fractions in simplest form.

3. Math Warm-up Find all of the factors of 40. See if you can find all 8.

4. Find all of the factors of 40. See if you can find all 8.
Math Warm-up - ANSWER
Find all of the factors of 40. See if you can find all 8.
1, 2, 4, 5, 8, 10, 20, 40
Pause to work.

5. In this lesson we will answer the question:
How can you write a fraction in Simplest Form?

6. Vocabulary
Greatest Common Factor: The greatest number that is a factor of 2 or more given numbers.
Example: 18=2 x 3 x 3
24=2 x 2 x 2 x3
Find the prime numbers!
Benchmark fraction: Common fractions used for estimating, such as ½, ¼, ⅓, ⅔, & ¾.

7. Vocabulary REVIEW Multiple: the result of multiplying two numbers.
Prime: a number that can be
divided evenly only by 1 or itself.
Composite: a number that can be
divided evenly by numbers other
than 1 or itself.

8. REVIEW Equivalent Fractions Connection to Level 4 Math
Some fractions are written differently as in this picture, but they each represent the same amount of pizza!

9. REVIEW Equivalent Fractions: Looking for a pattern.

10. Fractions in Simplest Form
A fraction is in simplest form when its numerator and denominator have no common factor other than 1. Examples: ½, ⅓, ⅔, ¼, ¾, ⅕, ⅜, ⅞

11. Fractions in Simplest Form
To write 12/20 in simplest form, find a common factor of the numerator and the denominator. Since 12 and 20 are even numbers, we know this fraction is NOT in simplest form. What do you know about EVEN numbers? They are divisible by 2, right?

12. Fractions in Simplest Form
12/20 in both the numerator and the denominator the factor of 2 is shared. 2 is a common factor. Divide both12 and 20 by ÷ 2 = 6 20 ÷ 2 10
Is this fraction 6/10 in simplest form? No

13. We need to change the fraction again until it cannot be divided any more?
12 ÷ 2 = 6 20 ÷ 2 10 Both 6 and 10 are even. We need to divide them by 2 again! 6 ÷ 2 = 3 10 ÷ 2 5
Is 3/5 in simplest form?
Yes, since 3 and 5 share no more common factors.

14. Fractions in Simplest Form
If a number is a factor of two numbers, it is called a common factor. The greatest common factor (GCF), of 2 numbers is the greatest number that is a factor of both numbers. 4 was the greatest common factor for both 12 & is a factor but we still did NOT have simplest form until we divided it by 4.

15. Simplest Form
Simplify the fraction.
common factor = common multiple
4 ÷ 2 = 2
3 (Is this fraction in simplest form?)
5 Can the numerator & denomInator be divided by a whole number?
(It was not in simplest form as it could be divided by ‘2’ for both the numerator & denominator.)
YES NO

16. Greatest Common Factor
The greatest common factor (GCF), of 2 numbers: 20 & 30 20: 1, 2, 4, 5, 10, 20 30: 1, 2, 3, 5, 6, 10, 15, 30 The GCF of 20 & 30 is 10. Or 10 is a multiple of both numbers.

17. Document Camera
Simplest
Form
Get your notebook
and pencil ready.
Make sure you have the Lesson # and date on your page.

18. Fractions in Simplest Form
Guided Practice

19. In your Math Notebook
Independent Practice 1. 2. 3. 4.

20. Independent Practice ANSWERS
In your Math Notebook
Independent Practice ANSWERS 1. 2. 3. 4.

21. In your Math Notebook
Quick Check
Some of the following fractions CANNOT be simplified. Simplify the ones you can.
Explain why some cannot be simplified, while others can be.

22. Quick Check Answers 1. No 2. No 3. YES…8/22 = 4/11 (÷ by 2)
Suggested Explanation:
#1 and #2 fractions can’t be simplified because they do not share factors other than 1.

23. Conclusion
Simplifying fractions , also known as, reducing or putting into lowest terms, means to make the fraction as simple as possible. They are still the same or equivalent but written with a different fraction name, as ½ = 2/4.
To simplify a fraction, divide the top and bottom by the highest number that can divide into both numbers exactly.

24. Good Work with this lesson.
Today you learned how to write a fraction in Simplest Form.