ADDING A

ND SUBTR

ACTING

FRACTI

ONS WIT

H LIKE

DENOMINAT

ORS

WHAT THE HECK IS A NUMERATOR AND DENOMINATOR?

Fractions are made of two parts; the numerator and denominator.

The numerator is the number on top of the fraction.

The denominator is the number on the bottom of the fraction.

HOW DO I ADD FRACTIONS WITH THE SAME DENOMINATOR?

To add or subtract fractions the denominators, or bottom numbers, must be the same.

THEN…

You simply add the numerators, or top numbers, and keep the denominators the same.

PRACTICE ON YOUR WHITE BOARD

1.

2.

3.

NOW PUT INTO SIMPLEST OR REDUCED FORM

Simplest or reduced form means that a number is reduced

LET’S PRACTICE!

We’re going to add: 3/6 + 1/6

Are the denominators the same?

Add the numerators, keep the denominator.

You should have gotten 4/6

Do you think we can reduce 4/6?

Yes!

NOW LET’S REDUCE!

First, we have to factor our numerator and denominator.

4: the factors of 4 are…1,2,4

6: the factors of 6 are…1,2,3,6

Which number in the two list is the Greatest Common Factor (GFC)

2

FINISH REDUCING

Now that we’ve figured out the GFC, divide the numerator and denominator by the GFC

4 2= 2

6 2 = 3

Our reduced fraction is now 2/3

MIXED NUMBERS AND IMPROPER FRACTIONS

Sometimes when we add fractions we get an improper fraction as our sum:

HOW TO TURN AN IMPROPER FRACTION INTO A MIXED NUMBER…IT’S SO EASY!

23/3 is an improper fraction

To make it a mixed number you simply have to divide the numerator, top number, by the denominator, bottom number.

23 3= 7 R 2

7 is your whole number, 2 becomes your numerator and 3 stays are your denominator.

NOW YOU TRY!

Turn each improper fraction into a mixed number

1. 15/2

2. 22/7

3. 9/2

Answers…

4. 7 ½

5. 3 1/7

6. 4 ½