Homework Help - Ahhh Fractions!

First things first - make sure you're math folder is open to your study guides (you will need them for help, and they are helpful I promise!!)

For tonights homework you should be adding/subtracting fractions with unlike denominators.

Step 1 : Find the LCM (Least Common Multiple -- use the slide method) of the DENOMINATORS

ex:        1/4    + 1/13  = ?

the only thing that can go into 4 AND 13 is 1. So using the slide method the LCM for 4 and 13 is  52

Step 2: Use Fraction x Fraction = Fraction so that the LCM is the NEW denominator.

ex: Our LCM is 52 so we want to change our fractions so that both denominators are 52.

    1/4    x     ?  /  ? =     ?  /52 (our LCM)       1/4      x    13/13    =   13/52

   1/13    x    ?   /  ?   =   ?  /52 (our LCM)         1/13    x     4/4     =     4/52

Step 3: Plug in new fractions then add or subtract.

ex: our original problem was

                                   1/4  +  1/13        but we changed 1/4 to 13/52
                                                                           we changed 1/13 to 4/52

                                13/52 + 4/52 = 17/52

Step 4: Check to make sure it is simplified

ex:    17/52     - 17 is a prime number so you cannot simplify 17/52 anymore