036 - RAGE + STUPIDMATH = I DON'T EVEN KNOW

[captain_slinky]

I can't find my screwdriver - the one I use for working on computers.

Meanwhile, there is a problem on Molly's Math homework that goes like this:

There are 45 kids in the Math Club. There are 4 times as many girls in the Math Club as there are Boys. How many Boys are in the Math Club? How many Girls? Explain your answer

Because I am frustrated over not being able to find my screwdriver, I can't figure out this problem AND I'm just getting angry at it for all sorts of reasons.

First, why are you asking me this? You OBVIOUSLY already have the answer, since you know how many kids are in the class AND you know that the number of boys versus girls is a ratio of four to one. Why are you wasting everyone's time with this question? I can not imagine a time in life - in ANY life other than the life of a pertson who makes up bullsh!t questions for 10-year-olds to answer - where I would be given this type of data and need to figure out the numbers that they already have.

Maybe it's that it's been presented as a "logic problem", despite the scenario being so illogical?

Yup, that's it. Instead of posing it as some Bridge Troll Riddle that I have to answer as part of his Questions Three or else in his stewpot 'tis where you'll find thee. Tricky Bridge Troll!

Because if I rewrite it into a practical question, I can work it out easily.

We need to make 45 donuts. We need there to be four times as many Chocolate Donuts as there are Plain Donuts. How many Chocolate and how many Plain do we need to make?

Comments

[hannah easterson (from livejournal.com)]

Sooo. Not sure if you genuinely want some homework help, but in case you do...I would solve this using algebra but I feel like 10 year-olds probably aren't getting to that yet? Either way, this is the easiest/best way to solve. If she's not using algebra yet, which I would be surprised if she was, I'm not really sure what solution the teacher is looking for. Here's how to solve using basic algebra.

In which g = girls and b = boys

g + b = 45 (because we know that there are 45 girls and boys total in the club)
and
g = 4b (because the number of girls is 4 times the number of boys. I.e. you'd have to have 4 times as many b to equal the number of g)

So since we know g = 4b, g and 4b are interchangeable. They mean the same thing. So let's go back and replace g with 4b in the first equation.

4b + b = 45

now 4b + b is the same as 5b. It's five times the number of b. Imagine if b was the number...2. It would still work 4(2) + 2 = 8 + 2 = 10. or simple 5(2) = 10. You follow me?

Ok. So

5b = 45. If this club was only boys, we'd need five times the number of boys that we have. But we don't need to know that. We need to know how many boys currently are in the club. Right?

So what's b? First we need to get rid of that five. We do that by dividing 5 from 5b. (division is the opposite of multiplication so...still with me?)

But you can't just divide b/5 and be done with it. Anything you do on one side of an equal sign, you have to do on the other. Think of it as a scale. If you want to keep the scale from tipping, you have to treat both sides the same. So we have to divide both sides by 5.

5b/5 = 45/5
or
b = 9.

Yay! Now we know that there are 9 boys in this club. Now the rest is easy. Just go back to one (or both) of those original equations.

b + g = 45

g = 4b

and just replace the b with 9. Solve for g. You can just do this in one or the other equation, but it's safer to do it in both just to be sure.

9 + g = 45.

to get rid of the 9, you have to subtract it. But remember, you have to subtract it from both sides. so

9 + g - 9 = 45 - 9. or g = 36

likewise

g = 4(9) or g = 36.

So: b = 9, g = 36.

You go girls. Teach those boys how to math.

[captain-slinky.livejournal.com]

It was the wording of the question that angered me beyond being able to work it. Once I made it about finding an actual solution rather than confirming data that they obviously already had. It's how my brain is wired I guess?

[hannah easterson (from livejournal.com)]

I totally understand that. I had the same problem when I was in school. If something is illogical or not something I can respect, it makes it impossible to care about. Like, obviously you know how many kids are in your math club, just count them! Why do you need to make this so complicated?!?! Word problems in math are the most inane things...

[aurora77]

Your wording is much more realistic than the wording of the other one. It's more like something that would come up in real life.

[pete23.livejournal.com]

Interesting. I read either question immediately as:

g = 4b
g + b = 45

and it takes a conscious "don't think of yellow penguins" effort not to slide straight into

4b + b = 5b = 45
b = 7, g = 38

Sometimes I like my maths brain, but sometimes people are genuinely telling you a story rather than expecting you to solve their simultaneous equations. Don't get me started on Voight-Kampff.