You thought we had forgotten about fractions, but they’re baaaaack! (Are you picturing wild-eyed Jack Nicholson wielding his ax in The Shining? Gives MURDER BY NUMBERS a whole new meaning, huh?) In the February 2005 installment, we explained the concept behind fractions, tackled the hard parts, and encouraged you to embrace them for the harmless, yet meaningful, little creatures that they are. Now we’re going to wrap things up, showing you how to divide and conquer without having to run away screaming.

Why do we have to deal with these things again?!? Because, despite the sleek, sexy nature of fractions’ counterpart – otherwise known as decimals – the world just cannot seam to let them go. Not only does the design industry still use them, but likewise…

• the construction industry [Cut me a 3-1/2 foot by 5-3/4 foot piece of plywood, will ya?];
• the cooking industry [Before bringing to a boil, add 1-1/4 teaspoons of salt and 1/2 tablespoon of white pepper.];
• the craft industry [Measure out 2-2/3 yards of rickrack and sew it 5/8” away from the edge of the rhinestones.];
• and many, many more.

Like we said before, we’ve really already covered the hard part [reducing, adding and subtracting], so it’s all downhill from here. Note: We’re starting with item #4 because we’ve already covered 1, 2 & 3 in the first installment.

Multiplying fractions is truly the easiest of all the ways to play with them. It may seem scary, but it is so basic that it’s liberating. All you do is simply multiply straight across:



These examples didn’t need it, but when multiplying, you can reduce the individual fractions down before or after multiplying. Exert your freedom of choice and do what you like:



OR



But what if you have fractions combined with whole numbers? Pretty much the same deal, except that you need to covert them into full fractions first, and then convert back when you’re done:



One more example:

Likewise, dividing fractions is a piece of cake. The trick to division is turning it into a multiplication problem instead. Say what? Yes, you read it right. Just take the fraction by which are dividing and flip it on its head, doing the multiplication thing after that. Let us show you an example using the fractions we just multiplied above:



OR



But, again, what do you do if you have fractions combined with whole numbers? Same old story: convert, divide, and convert again:

6) Fractions As Percentages & Percentages As Fractions

We’ll end with the super easy part: converting fractions to a percentage and vice versa. Percentages are really fractions anyway – a number over 100 – so it makes perfect sense. It’s all about division (but not the flip! kind).



And another example:



Now what about turning things around to add a little spice?



One more example:

More To Come
So there you go. See, it wasn’t nearly as hard as you thought it was going to be, was it? Except for FORTRAN computer language and organic chemistry, most things usually aren’t. Just wait until we get into decimals and proportions and things – you are going to be so math empowered that you won’t be able to stand it. Stay tuned.