How to add and subtract unlike denominator fractions. Numerator (top number), Denominator (bottom number)










Do the fractions have the same denominator?
 NO

Find the least common multiple (LCM). Remember that's a list of the multiples, use a X's chart if you want.


Circle the LCM so you can create an equivalent fraction where the denominator is the same as the LCM. Do this for both fractions. See next step.

 
 
YES









Add or subtract the numerators and keep the denominators the same. YOU ARE DONE!


Figure out what number can be multiplied by the old denominator so it is equal to the new denominator (that you found using LCM).


Multiply the numerator and denominator by the same number (whatever you do to the top, you have to do to the bottom).

 
 











Rewrite your new equation and solve.

 
 
 










 
 
 
 










 
 
 
 










 
 
 
 










 
 
 
 








