Multiplying/Dividing Fractions with Different/Unrelated Denominators (7)

Multiply and divide fractions and decimals using efficient written strategies and digital technologies (ACMNA154)

LO: To multiply or divide fractions with unrelated denominators.
Know:

  • how to multiply/divide numbers

Understand:

  • that the multiplication of fractions makes the fractions larger
  • that the subtraction of fractions makes the fractions smaller
  • that when adding/subtracting fractions, you have to keep the denominator the same. If they are different you have to make them the same prior to proceeding.

Do:

  • I can multiply and divide fractions

Visual Representations

Notes

When multiplying fractions with the different/unrelated denominators, you don’t have to do anything special. All you have to do is numerator multiply by the numerator and denominator multiplied by denominator.

When dividing fractions with the different/unrelated denominators, it’s a little bit more complicated. What you have to do is flip (find the inverse) the second fraction then proceed as if your multiplying the fractions. Numerator multiplied by the numerator and denominator multiplied by the denominator.

Multiplying and Dividing Fractions Videos

Multiplying

Dividing

Textbook Questions

My Maths 7

Exercise 2D pg. 86 Q. 3-7

Exercise 2E pg. 92 Q. 6-9, 10-22

My Maths 8

Exercise 1D pg. 25 Q. 4

Other Resources

Mathis Fun -Division
Mathis Fun Multplication
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