Multiplying Fractions

Grade 9 Applied MathematicsM. M. Couturier

Multiplying Fractions

• If you know how to add and subtract fractions, then you already know how to multiply fractions!!!

Multiplying Fractions

• Let us take the following example:

• (2)(2) (3)(5)

• The denominators are not the same; WHO CARES; this is multiplication!!!

Multiplying Fractions

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

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!!!

Multiplying Fractions

• Let’s do another example: • (2)(1)

(3)(4) • 2

12 • In this case, we need only simplify

the fraction:• 1

6

THE BLUEPRINT

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

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!!!

WWW • Let us visit the world wide web:

• http://www.aaamath.com/fra66m-multfract.html

WWW • Let us visit the world wide web:

• http://www.aaamath.com/B/fra66mx2.htm

WWW • For those who are visual:

• http://www.visualfractions.com/multiply.htm