samgelinas: Put them on the same denominator. (I don't know if it's this in English but in french we say "denominateur"...)
Hi Sam,
Denominator is the right word
It really depends what you want to do with them That is add, subtract, multiply or divide. ?
Here is a unit you should probably work through.
http://www.mathsisfun.com/mixed-fractions.html
And if you google 'Working with mixed numerals' you will get a list of other useful websites including some you tube clips.