5-4 Part 2: Dividing Fractions

Now then - on to dividing with fractions. 

I'm about to tell you the most well-kept secret about fractions: You don't have to. 

?!

It's true. 

Dividing by a fraction is very simple once you learn the two main steps. 

Step 1:

Change the problem to a MULTIPLICATION problem instead. For example: 

2/3 ÷ 1/4 becomes 2/3 x 1/4. The most important step is next. 

Step 2: 

"Flip" the second number (or, in other words, find the reciprocal of the divisor - a reciprocal is the inverse - the number gets flipped around). It's that simple. So for our example above, we would "flip" 1/4 and turn it into 4/1. Our math problem is now this:

2/3 x 4/1

Now we can use what we learned yesterday to multiply the fractions. First, the tops:

2 x 4 = 8

Then, the bottoms:

3 x 1 = 3

Our new fraction is 8/3. We must simplify:

8/3 = 2 2/3 (two and two-thirds)

It's that simple. Just change it to multiplication and make SURE you flip that second number. If you run into mixed numbers, same thing from yesterday applies - just transform the mixed number into an improper fraction first. 

Let's try pg. 255, 18 - 28.