The 44th President of the United States of America.

Chapter 5Section 3: Adding and Subtracting Fractions.

November 5th, 2008

The Day After Election Day.

Same Denominator, Easy Cheesy

When the DENOMINATOR is the same

just add or subtract

the NUMERATOR.

Like These

• 3/7 + 1/7 =

• 2/k + 3/k =

• 7/10 – 3/10 =

• (11/y) + (-5/y) =

From Yesterday

To add or subtract fractions with unlike denominators:

Write the fractions with a common denominator (LCM).

A/B + C/D = ?If you can’t find the LCM, make up one.

Simplify Each: Difference or Sum

-7/8 + ¾ =

1/8 – 5x/6 =

3/7 + 2/m =

Adding/Subtracting/Mixed Numbers

Before Adding/Subtracting Mixed Numbers, Make Them Into Improper Fractions!

5 ¾ + 7/8 =

25 1/3 + 3 5/6 =

2 3/8 + 7/16 =

Chapter 5Section 4: Multiplying and

Dividing Fractions

Multiplying Rational Numbers

Rational Numbers are Numbers that can be EXPRESSED as a Fraction, or Ratio!

Multiply the Numerators and Denominators

(2/5)(1/3) =

(-5/6)(2/3) =

Simplify Before You Multiply

When a Numerator AND Denominator have COMMON FACTORS, you can Simplify

before Multiplying.

(9/15)(5/9) = (y/4)(8/11)=

Multiply and Simplify

(-5/14)(21/25) =

(2x/9)(3/4) =

(2/3)(6/7) =

Multiplying Mixed Numbers?

Convert to an

IMPORPER FRACTION,

then SIMPLIFY.

Word Problem

• Central Park in New York City is a rectangle. It is approximately 2 ½ miles long and ½ miles wide. What is the area of Central Park? (Formula: A = LW)

Find Each Product

• (3 ¾)(2/5) =

• (2/3)(1 2/7) =

• (-2 5/6)(1 3/5) =

Dividing Rational Numbers

3 ½ = Is the same as saying:

“How many haves are in three wholes?”

Reciprocal

2/1 (or 2) and ½ are RECIPROCALS.

Every number can be written as RATIONAL number, which

means it has a RECIPROCAL.

Reciprocal

The PRODUCT of two RECIPROCALS is 1.

Dividing Fractions

To Divide Fractions…

1) Make the SECOND fraction into it’s RECIPROCAL.

2) Change the Division operation INTO a MULTIPLICATION operation.

3) Then MULTIPLY.

4) Don’t forget to Simplify If Possible!

Divide These Fractions

• (2/9) (2/5) =

• (x/3) / (x/4) =

• (-1/4) (1/2) =

Divide This!

• (5x/9) / (10x/27) =

• (-1 3/5) (-1 1/5) =

• (12 ½) / (1 2/3) =

Assignment #34

Page 238: 21-35 Odd.

Page 243: 19-49 Odd.