So a friend recently posted this on a message board I frequent. Since childhood, I’ve had some odd ability to do simple [operator] math in my head very quickly. The following test is exactly that:
So a friend recently posted this on a message board I frequent. Since childhood, I’ve had some odd ability to do simple [operator] math in my head very quickly. The following test is exactly that:
Instructions. [wink]
“Ignore all that and take the test anyway.” [smiley]
He got me, I admitted it. Now I’m genuinely curious to see how folks do.
I saw something similar a few weeks ago (It got me the first time too), so I knew where it was going once I saw the math problems and the “story”.
Maybe you can get a job at McDonald’s and figure out why…
biscuit = 1.39
biscuit + sausage = 1.00
2:38… and no, I’m not bullshitting.
Really Christopher? All in your head? 100% correct? That’s pretty good.
Yeah… like you, I have an innate ability to do arithmetic in my head. I’m guessing you got 700+ in math on your SATs? We used to have those speed math tests in elementary school and I’d rock them out.
I “see” the numbers so it’s kinda like doing it on paper. I actually think I have a touch of Asperger Syndrome because when people talk numbers in conversation, I have to figure out the answer. Ironically, that may explain why people think I’m an asshole. Wikipedia says “The lack of demonstrated empathy is possibly the most dysfunctional aspect of Asperger syndrome.”
Very interesting. Yeah, 750.
So 486*4. How did you do it?
I did 4*400 = 1600 and stored that in my head.
Then 4*80 = 320. Add the 1600 and we’re at 1920.
Then 4*6 = 24. Add that on and we’ve got our answer.
Stupid me, I’m getting rusty. Would have been way quicker to realize 486 is 14 less than 500. 500*4 = 2000, minus 4*14 = 56… 2000-56 = answer. Damn.
That’s exactly how I did it. I think people have a problem because they can’t store the 1600 and 320 long enough to add it all back together. That and they’re taught to work from the right most digit, which is fine on paper but sucks for doing it in your head.
For whatever reason, 44/16 tripped me up more. I did 16×2=32 but then couldn’t figure out what (44-32)/16 was. I should have been focusing on 44-32 but the 16 kept popping into my head and messing me up. I defaulted to 8 as the numerator because it went nicely with 16, but I knew that was wrong so I had to concentrate (too long) on it.
Errr… the first way you mentioned is how I did it. I do things the second way you mentioned, but only when it’s like <10 below the rounded number.
Yay us!
“Maybe you can get a job at McDonald’s and figure out why…
biscuit = 1.39
biscuit + sausage = 1.00″
It’s related to inventory, they order each item in bulk (sausage + biscuit) in matching quantities for whatever the combination might be. They’ve probably done an analysis showing 95 (or higher) percent of biscuits purchased are done so via a sandwich order, so in order to prevent running out of different sandwich components at different times they create a discouraging price differential between individual items and combinations. This prevents having to order product in unmatching quantities or at different times (saves on shipping costs by delivering items in bulk in one trip as opposed to ad hoc deliveries), etc. etc.
Jbitties – You need to stop thinking about the sausages so much
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