Facebook Sunday Morning Math Problem

So a friend posted this today, and I think I argued with teacher(s) on it, so now it's a blog. Read it and when you see it on Facebook, you can be all smarty pants, and then when asked to explain, copy and paste my explanation at some point. See? Now you are a smart ass like me. Moving on up in this world ay?

I'm going to share a secret. I'm a math geek, but a shitty one. When I first encountered a problem like this, from a public facebook page, I was in google for hours trying to figure it out. I read a hundred comments. It took me forever to figure it out to where I was confident in my answer, confident enough to post it as my Dribble and Grits page. So when my friend posted it, I already was 3 steps ahead of her friends with the google and hair pulling. I think they are still in google as I type this. Poor things. They should have just took my word for it. So now, maybe Google will find it and you will see this.

One problem. Multiple ways to approach the answer. (Hint: the last one is the best one for people like me).

6 / 2 (1 + 2) = ?

The answer is 9.


1. Following PEDMAS (Please Excuse My Dear Aunt Sally), you first solve 1+2 to get 3. Parentheses first right? Then you hit multiplication and division left to right so 6/2 is 3 and 3 times 3 is 9.


6 / 2 (1+2)
6 / 2 (3)
3 (3)
9


2. 6 divided by 2 is a fraction. Many people feel tempted to multiply the parentheses with just the denominator. We don't do that without brackets telling us to otherwise. You multiply fractions with the numerator. If I said half of 6, that's 3 easy right? So let's do it mathematically to get that 3 in this example...

1/2 (6)
1/12 WRONG that's not 3.
6/2 RIGHT that's 3.

So...

6/2 (3)
18/2
9


or better shown visibly...
6/2 x 3/1 = 18/2 = 9

3. Let's have some more fun with word problems and see if it makes any "common sense."

New problem example: If you have 1/2 of a pie and Jesus Christ was able to multiply it 3 times, you would end up with 1.5 pies. 1/2 (3)... Answer 3/2 (or 1.5) not 1/6.


So if you have 6 eggnogs divided by 2 bloody marys times 3 hot toddies --- is it 1 drink or 9? The answer is definitely schnockered, and you can't get that from one drink.