Dividing Fractions



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: |Make 1 ½ an improper fraction of 3/2 |

|[pic] ÷ [pic] = ? |First convert all whole numbers and mix number to improper fractions |Change the division sign to multiplication |

| |Then change the division sign to a multiplication sign |Invert the second fraction |

| |Next invert (flip) the second fraction in the problem | |

| |Use cancellation if you can |3 ÷ 3 = 3 x 9 = 31 x 9 = 9 ; |

| |Next Multiply the numerators of the fractions |11 9 11 3 11 31 11 |

| |Multiply the denominators of the fractions |Cancel out the numerator 3 with the denominator 9 by the common |

| |Place the product of the numerators over the product of the denominators |factor 3. |

| |Simplify the fraction if necessary |Then multiply the numerators and denominators. |

| | |You get 9/11. |

|EXAMPLE 2: |To Divide Fractions: |Make 1 ½ an improper fraction of 3/2 |

|[pic] ÷ [pic] = ? |First convert all whole numbers and mix number to improper fractions |Change the division sign to multiplication |

| |Then change the division sign to a multiplication sign |Invert the second fraction |

| |Next invert (flip) the second fraction in the problem | |

| |Use cancellation if you can |7 ÷ 1 ½ = 7 ÷ 3 = 7 x 2 1 = 7 x 1 = 7 ; |

| |Next Multiply the numerators of the fractions |10 10 2 5 10 3 5 x 3 15 |

| |Multiply the denominators of the fractions | |

| |Place the product of the numerators over the product of the denominators |Cancel out the numerator 2 with the denominator 10 by the common |

| |Simplify the fraction if necessary |factor 2. |

| | |Then multiply the numerators and denominators. |

| | |You get 7/15 |

|EXAMPLE 3: |To Divide Fractions: |Make 1 ½ an improper fraction of 3/2 and 18, 18/1 |

|[pic] ÷ 18 |First convert all whole numbers and mix number to improper fractions |Change the division sign to multiplication |

| |Then change the division sign to a multiplication sign |Invert the second fraction |

| |Next invert (flip) the second fraction in the problem | |

| |Use cancellation if you can |3 ÷ 18 = 3 ÷ 18 = 13 x 1 = 1 x 1 = 1 ; |

| |Next Multiply the numerators of the fractions |2 1 2 1 2 186 2 x 6 12 |

| |Multiply the denominators of the fractions | |

| |Place the product of the numerators over the product of the denominators |Cancel out the numerator 3 with the denominator 18 by the common |

| |Simplify the fraction if necessary |factor 3. |

| | |Then multiply the numerators and denominators. |

| | |You get 1/12. |

|1) |To Divide Fractions: |Work Space |

|[pic] ÷ [pic] = ? |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 | |

|2) |Work Space |

|[pic] ÷ [pic] = ? | |

|3) |Work Space |

|[pic] ÷ [pic] = ? | |

|4) |Work Space |

|[pic] ÷ 33 = ? | |

|5) |Work Space |

|[pic] ÷ [pic] = ? | |

|6) |To Divide Fractions: |Work Space |

|[pic] ÷ [pic] = ? |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) |Work Space |

|[pic] ÷ [pic] = ? | |

|8) |Work Space |

|[pic] ÷ [pic] = ? | |

|9) |Work Space |

|20 ÷ [pic] = ? |6 ¼ |

|10) |Work Space |

|1[pic] ÷ [pic] = ? | |

|11) |To Divide Fractions: |Work Space: |

|3 ÷ [pic] = ? |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 | |

|12) |Work Space |

|19 ÷ [pic] = ? | |

|13) |Work Space |

|[pic] ÷ 14 = ? | |

|14) |Work Space |

|[pic] ÷ [pic] = ? | |

|15) |Work Space |

|8 ÷ [pic] = ? | |

|16) |To Divide Fractions: |Work Space |

|[pic] ÷ [pic] = ? |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 | |

|17) |Work Space |

|[pic] ÷ [pic] = ? | |

|18) |Work Space |

|62 ÷ [pic] = ? | |

|19) |Work Space |

|[pic] ÷ [pic] = ? | |

|20) |Work Space |

|[pic] ÷ [pic] = ? | |

Activity 1: Division of Fractions Review

Go to the internet. Type this website in the address bar: 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.

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Activity 3: Math Lab – Dividing Fractions

Go to the internet. Type this website in the address bar: fracdivw.htm

[pic]

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.

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