combining fractions- 1510

How many ways can we combine or mix up some fractions? A few.  We can add them, multiply them, divide them and subtract them.  I like this kind of math, it feels like a fancy occasion.  Really? You doubt? What does one wear to a fancy schmancy occasion...if you're male and like to dress up?  A bow tie!! See? Fancy.  We use the bow tie when we ADD or SUBTRACT fractions when the denominators are not the same.  A bow tie fixes it all up and neatly, I might add.  See? I made this little demonstration for you...

Works like a charm because bow ties are just that, charming. Even Pee Wee knows that bow ties work.


Bow ties are a great way to show kids how to get matching denominators in a snap.  Of course, they can also use a factor tree to find the least common multiple and certainly we can teach them that method as well but the bow-tie is just so neat and tidy.

We can also multiply fractions and in my humble opinion, this is easier than adding them.  Multiplying fractions is so easy that you just multiply the numerators and multiply the denominators. It is really that easy.  Don't believe me? Then google it. This rule is everywhere out there on the internet, not just in Wikipedia either.  I even found a game that could be used in a classroom setting. It is based on the Millionaire game and the teacher can use it with a SMART board since it would be fun for a touch screen application.  There is a solo option or a team option.  Try it here at Math-play.com

We know that division is the opposite of multiplication so dividing fractions just involves a little twist or flip.  When we have two fractions to work with, invert the second and multiply.  Something like this...

Very simple process.  Why does it work? Because division is the inverse operation of multiplication.  And where do I go to make all these lovely visual aides?  Picnik, of course!  It is a great resource to modify photos and create pictures with some personality.