Saturday, October 22, 2011

Zapping Fractions -- Division Math

Dividing Fractions can be fun when you bring in a magician. Although this can be done with a paper and pencil, we found it helpful to use manipulatives and spread it out on the floor. Start with a deck of number cards. Our favorites are the "Number Jugglers" cards, but Uno cards work well too. Create the fraction you want to divide. We were dividing mixed numbers, but simple fractions will work well too. We used math rods to create the line between the numerator and the denominator. Create an operation dice or block with a division sign on one side and a multiplication sign on the other. Find an object that can be the magic wand (We used a canning lid magnet). 
Here's how it works.  
If you are dividing mixed numbers you first need to change them into improper fractions, as my daughter did in the first picture. Then imagine that the first fraction is a magician and is going to zap the other fraction. Then get the magic wand and say the magic word: "Reciprocal!" And point the wand at the 2nd fraction and flip it around so the numerator is on the bottom and the denominator is now on the top. Then zap the operation dice so the multiplication symbol now shows as in this picture.
 Then zap the numbers as you do cross cancelling before you multiply the fractions. Use math rods to "cross out" the numbers and number cards to show the new number. If your product is an improper fraction, then change the answer back into a mixed number.
 Edible Variation:Put a piece of candy over the first fraction to represent the magician's hat. Then after the problem is done correctly then the student can eat the treat. If doing this on paper, a chocolate chip "magician hat" could be put over the first fraction.

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