Arithmetic Grade Five

Lesson One Hundred and Eleven: Whole-Fraction Division I

Dividing by fractions can sometimes be a little confusing. So, let's start with a story: 


	Let's say that you have four candy bars and
	that you want to divide each one into four
	pieces. How many pieces will you wind up with?

	In other words, you want to divide four candy
	bars into four pieces each. Each piece will be
	one-quarter of a candy bar. 

	We can write this as a division problem like this:

	4 ÷ 1/4 =
You probably realize at this point that the answer is 16, but how do we perform division with fractions?

You've probably already realized that we could also get the answer by multiplying 4 and 4. This gives us a really good hint about the procedure used to solve these division with fractions problems. 


	PROBLEM: 4 ÷ 1/4 =

	STEP ONE: Flip the second fraction and change 
		  the operation to multiplication. (4 x 4/1 = )	

	STEP TWO: Multiply. (4 x 4/1 = 16) 
		  Remember that 4/1 = 4.
Here's another example: 

	PROBLEM: 3 ÷ 1/5 =

	STEP ONE: Flip the second fraction and change 
		  the operation to multiplication. (3 x 5/1 = )	

	STEP TWO: Multiply. (3 x 5/1 = 15)

Now you get to try a few.

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