Dividing Fractions (3 Column Method)

Dividing Fractions (3 – Column Method)

When dividing fractions, invert the second fraction and use the same rules for multiplication.
Examples / Definitions / Set Up & Solve
EXAMPLE 1:
÷ = ? / To Divide Fractions:
·  First convert all whole numbers and mix number to improper fractions
·  Then change the division sign to a multiplication sign
·  Next invert (flip) the second fraction in the problem
·  Use cancellation if you can
·  Next Multiply the numerators of the fractions
·  Multiply the denominators of the fractions
·  Place the product of the numerators over the product of the denominators
·  Simplify the fraction if necessary / 1)  Make 1 ½ an improper fraction of 3/2
2)  Change the division sign to multiplication
3)  Invert the second fraction
3 ÷ 3 = 3 x 9 = 31 x 9 = 9 ;
11 9 11 3 11 31 11
4)  Cancel out the numerator 3 with the denominator 9 by the common factor 3.
5)  Then multiply the numerators and denominators.
6)  You get 9/11.
EXAMPLE 2:
÷ = ? / To Divide Fractions:
·  First convert all whole numbers and mix number to improper fractions
·  Then change the division sign to a multiplication sign
·  Next invert (flip) the second fraction in the problem
·  Use cancellation if you can
·  Next Multiply the numerators of the fractions
·  Multiply the denominators of the fractions
·  Place the product of the numerators over the product of the denominators
·  Simplify the fraction if necessary / 7)  Make 1 ½ an improper fraction of 3/2
8)  Change the division sign to multiplication
9)  Invert the second fraction
7 ÷ 1 ½ = 7 ÷ 3 = 7 x 2 1 = 7 x 1 = 7 ;
10 10 2 5 10 3 5 x 3 15
10)  Cancel out the numerator 2 with the denominator 10 by the common factor 2.
11)  Then multiply the numerators and denominators.
12)  You get 7/15
EXAMPLE 3:
÷ 18 / To Divide Fractions:
·  First convert all whole numbers and mix number to improper fractions
·  Then change the division sign to a multiplication sign
·  Next invert (flip) the second fraction in the problem
·  Use cancellation if you can
·  Next Multiply the numerators of the fractions
·  Multiply the denominators of the fractions
·  Place the product of the numerators over the product of the denominators
·  Simplify the fraction if necessary / 13)  Make 1 ½ an improper fraction of 3/2 and 18, 18/1
14)  Change the division sign to multiplication
15)  Invert the second fraction
3 ÷ 18 = 3 ÷ 18 = 13 x 1 = 1 x 1 = 1 ;
2 1 2 1 2 186 2 x 6 12
16)  Cancel out the numerator 3 with the denominator 18 by the common factor 3.
17)  Then multiply the numerators and denominators.
18)  You get 1/12.
1)
÷ = ? / To Divide Fractions:
·  First convert all whole numbers and mix number to improper fractions
·  Then change the division sign to a multiplication sign
·  Next invert (flip) the second fraction in the problem
·  Use cancellation if you can
·  Next Multiply the numerators of the fractions
·  Multiply the denominators of the fractions
·  Place the product of the numerators over the product of the denominators
·  Simplify the fraction if necessary / Work Space
=
2)
÷ = ? / Work Space
3)
÷ = ? / Work Space
4)
÷ 33 = ? / Work Space
5)
÷ = ? / Work Space
6)
÷ = ? / To Divide Fractions:
·  First convert all whole numbers and mix number to improper fractions
·  Then change the division sign to a multiplication sign
·  Next invert (flip) the second fraction in the problem
·  Use cancellation if you can
·  Next Multiply the numerators of the fractions
·  Multiply the denominators of the fractions
·  Place the product of the numerators over the product of the denominators
·  Simplify the fraction if necessary / Work Space
7)
÷ = ? / Work Space
8)
÷ = ? / Work Space
9)
20 ÷ = ? / Work Space
6 ¼
10)
1 ÷ = ? / Work Space
11)
3 ÷ = ? / To Divide Fractions:
·  First convert all whole numbers and mix number to improper fractions
·  Then change the division sign to a multiplication sign
·  Next invert (flip) the second fraction in the problem
·  Use cancellation if you can
·  Next Multiply the numerators of the fractions
·  Multiply the denominators of the fractions
·  Place the product of the numerators over the product of the denominators
·  Simplify the fraction if necessary / Work Space:
12)
19 ÷ = ? / Work Space
13)
÷ 14 = ? / Work Space
14)
÷ = ? / Work Space
15)
8 ÷ = ? / Work Space
16)
÷ = ? / To Divide Fractions:
·  First convert all whole numbers and mix number to improper fractions
·  Then change the division sign to a multiplication sign
·  Next invert (flip) the second fraction in the problem
·  Use cancellation if you can
·  Next Multiply the numerators of the fractions
·  Multiply the denominators of the fractions
·  Place the product of the numerators over the product of the denominators
·  Simplify the fraction if necessary / Work Space
17)
÷ = ? / Work Space
18)
62 ÷ = ? / Work Space
19)
÷ = ? / Work Space
20)
÷ = ? / Work Space

Activity 1: Division of Fractions Review

Go to the internet. Type this website in the address bar: www.thatquiz.com to take the lesson review. Use this class test code: QZJS0730. If you score less than 80% on the quiz, try it again and use LJGX7302.

Activity 3: Math Lab – Dividing Fractions

Go to the internet. Type this website in the address bar: www.mrnussbaum.com/fracdivw.htm

Scroll down. Click the drop down arrow. Find the correct answer and click it.

Click check to check your answers. Record your score here: .

Activity 3: Do the next lesson in Basic Skills Interactive.

De Etta Ryan, Instructor/Developer ABE 3 Math - Fractions Page 6

3.3.0 – 3.3.6