1. Multiplying Fractions Grade 9 AppliedMathematics M. M. Couturier

2. Multiplying Fractions • If you know how to add and subtract fractions, then you already know how to multiply fractions!!!

3. Multiplying Fractions • Let us take the following example: • (2)(2) (3)(5) • The denominators are not the same; WHO CARES; this is multiplication!!!

4. Multiplying Fractions • In multiplication, regardless of the numbers you simply multiply ALL the numerators and then you multiply ALL the denominators.

5. Multiplying Fractions • Hence in the case of: • (2)(2) (3)(5) • The numerators are 2x2=4 and the denominators are 3x5=15; hence, • 4 15 • DONE!!! QED!!!

6. Multiplying Fractions • Let’s do another example: • (2)(1) (3)(4) • 2 12 • In this case, we need only simplify the fraction: • 1 6

7. THE BLUEPRINT • The following will work for ALL multiplications of proper fractions.

8. THE BLUEPRINT • Let us recall our strand in algebra: • (a)(c) (b)(d) • ac bd • The ironic thing about multiplying fractions is that it is easier than addition and subtraction!!!

9. WWW • Let us visit the world wide web: • http://www.aaamath.com/fra66m-multfract.html

10. WWW • Let us visit the world wide web: • http://www.aaamath.com/B/fra66mx2.htm

11. WWW • For those who are visual: • http://www.visualfractions.com/multiply.htm