Scribe Post for November 20, 2009

Hey guys, during Friday's class we talked about Reciprocals.

Hmm what are reciprocals ? Well let me explain them to you.

Reciprocal - two factors that when multiplied will give the product of one.

For example,

(5/11)(11/5) = 1

(2/3)(3/2) = 1

3/4 x 4/3 = 1

Identity of one

- any number multiplied by one is itself

- any number divided by one is itself

Ex.

1 x 18 = 18

( one times a group of eighteen ) = eighteen

1/2 ÷ 1 = 1/2

So here are the steps if using reciprocals

1. find the reciprocal of the divisor

2. multiply the dividend and divisor by the reciprocal of the divisor

3. divisor becomes one, anything divided by one is itself

4. simplify if possible

So heres a question using a reciprocal

24/35 ÷ 3/7 = 24/35 x 7/3 ( 3/7 x 7/3 ) reciprocal

= 24/35 x 7/35

= 8 x 1/5

= 8/5

= 1 3/5