We are doomed if this is the kind of math we don't know.

[exdeath]

Wanna really screw with 'em? When you see the amount comes out to, say, $4.55, hand them a $5 bill. Let them punch that amount into the cash register, which will tell them they need to give you $0.45 change.

Now, before they start counting out the change, hand them $0.55, and watch the show begin! I cannot count the number of times I have seen pure confusion on the face of a cashier, because they can't figure out that they now owe you $1!!

It's really sad.....and I'm a dick for doing it......but I can't help myself!! :whiste:

LOL

Math fanatic here. Calc III, ODE, PDE, and linear algebra with 4.0.

Didn't even need vector for C.Sc. but for some reason I wanted to compete all available undergrad math courses.

Surprising, quite a bit is used in 3D graphics. Surface integrals, Greens Theorem, vector fields for normals of runtime generated surfaces, etc.

Problem most people have isn't that they are "math dumb", its just short term memory and doing stuff in your head on the spot. Especially when you do math sequentially and iteratively like taught in school instead of much much simpler MADD operations of place groups in parallel.

99x99 for example they try like they learned in school. 9x9 is 81, carry the 8, etc and their short term memory is quickly fried and you get the deer in headlights look. Instead, 99x100-99 = 9900-99 = 9900 - 100 + 1 is MUCH easier and requires NO short term memory.

 

[Zodiark1593]

I myself can easily perform arithmetic in my head, and even a fair portion of Algebra, which actually caused me to fail a few tests due to not showing my work.

 

[Eug]

I had an argument once with a cashier. The bill came to $12.99 (or something like that), and after I handed her a $20 bill she asked me for a penny so that should could give me bills with no change.

Yes, I argued over a penny, but I was just incredulous she couldn't do that basic math in her head.

 

[SparkyJJO]

I myself can easily perform arithmetic in my head, and even a fair portion of Algebra, which actually caused me to fail a few tests due to not showing my work.

I hated that note "SHOW YOUR WORK" and points taken off on problems even though I had the answer right. So irritating, especially when just doing the problem in the head took less time than writing it all out.

Once I wrote it out as long as I possibly could out of spite. That didn't go over too well either

 

[DrPizza]

Wanna really screw with 'em? When you see the amount comes out to, say, $4.55, hand them a $5 bill. Let them punch that amount into the cash register, which will tell them they need to give you $0.45 change.

Now, before they start counting out the change, hand them $0.55, and watch the show begin! I cannot count the number of times I have seen pure confusion on the face of a cashier, because they can't figure out that they now owe you $1!!

It's really sad.....and I'm a dick for doing it......but I can't help myself!! :whiste:

Bah. Wait til it's $7.87, give them a 10, then as they punch it in, say, "here's another $3.12 to make the change a lot easier for you."

 

[Eug]

I hated that note "SHOW YOUR WORK" and points taken off on problems even though I had the answer right. So irritating, especially when just doing the problem in the head took less time than writing it all out.

Once I wrote it out as long as I possibly could out of spite. That didn't go over too well either

I never understood this attitude. The whole point of showing your work is to prove you actually know how to do it.

Sometimes you can get most of the way through but then get stuck. And then you can guess and get the right answer, but I don't think that deserves the same credit as someone who actually does it correctly and systematically.

If I were a teacher, I would do the exact same thing. It's not my problem if the student is too lazy to show his/her work.

 

[zerocool84]

That's why I have a calculator on my phone.

 

[jagec]

Sometimes you can get most of the way through but then get stuck. And then you can guess and get the right answer, but I don't think that deserves the same credit as someone who actually does it correctly and systematically.

The problem is that the teacher's idea of "correctly" is usually the inefficient standard way, which isn't how smart people do math.

For example, doing an addition problem from right to left (standard) instead of from left to right (faster, AND with the added bonus of giving you an iteratively better answer as you work through the problem).

Math is full of things like that. Smart kids are constantly frustrated by math teachers insisting that they do things the stupid way, because that's all that their classmates can manage.

 

[Eug]

The problem is that the teacher's idea of "correctly" is usually the inefficient standard way, which isn't how smart people do math.

I agree that crappy teachers suck, but back in high school pretty much all of my math teachers were quite reasonable about this stuff. If you show your work, then they can work through it and give credit when credit is due, even if the methodology is not exactly the same as they expected.

 

[Pray To Jesus]

Wanna really screw with 'em? When you see the amount comes out to, say, $4.55, hand them a $5 bill. Let them punch that amount into the cash register, which will tell them they need to give you $0.45 change.

Now, before they start counting out the change, hand them $0.55, and watch the show begin! I cannot count the number of times I have seen pure confusion on the face of a cashier, because they can't figure out that they now owe you $1!!

It's really sad.....and I'm a dick for doing it......but I can't help myself!! :whiste:

If cashier is smart, "Thanks for the tip!" Gives back $0.45 and pocket the $0.55.

Watch confusion on mm's face as hilarity ensues.

 

[AViking]

Wanna really screw with 'em? When you see the amount comes out to, say, $4.55, hand them a $5 bill. Let them punch that amount into the cash register, which will tell them they need to give you $0.45 change.

Now, before they start counting out the change, hand them $0.55, and watch the show begin! I cannot count the number of times I have seen pure confusion on the face of a cashier, because they can't figure out that they now owe you $1!!

It's really sad.....and I'm a dick for doing it......but I can't help myself!! :whiste:

Lol I used to do this all the time.

When I was a little kid the bill for candy would often end up being either $1.05 or $0.95 and I realized really quick that people struggled immensely with numbers like this. $0.95? Hand them $1.05 or $1.30. They can't deal with it.

 

[Maximilian]

I call that stuff arithmetic, math is more complex.

Im generally shit at arithmetic but ive gotten better recently because my diet massively revolves around milk so i now go around working out how much skimmed milk equivalent something is. Its 50p per litre of skimmed milk so I could have 10 litres of milk or this 1 chicken which is £5, more protein in the milk! Its gotten more complex recently as ive started using milk powder instead so 1 box of milk powder is £1.15 and that makes 4 litres of milk so i can have 4 boxes for that chicken and that makes 16 litres of milk with 40p left over.

Bought a £35 drill recently, that's 120 litres of milk powder derived milk...

Im fucking weird, no shame!

 

[Exterous]

I'll admit that I occasionally hand my wife math stuff to do and say "We paid thousands of dollars in tuition so you can do this stuff, best we make it count." Requires even less work on my part than a calculator!

I hated that note "SHOW YOUR WORK" and points taken off on problems even though I had the answer right. So irritating, especially when just doing the problem in the head took less time than writing it all out.

While I often found it annoying I can understand it from a teacher's point of view in a number of situations. If you get it wrong was it an arithmetic error or a procedural one? Did you just cheat and look at someone else's answer and copy it down? Use a calculator on a 'no calculator allowed' test? etc etc

 

[rudeguy]

pics of the girl?

 

[Jaskalas]

I hear her say, "no, 806 is not halfway between 800 and 900. Count to 900 for me, starting from 800."

Eww... counting. How do they ever expect to realize the obvious answer from that?

 

[foghorn67]

Bah. Wait til it's $7.87, give them a 10, then as they punch it in, say, "here's another $3.12 to make the change a lot easier for you."

Why would you do that? Do you troll in real life? just for your amusement?
You sound like a great guy. :whiste:

How about teaching them to count up? It's not even math.

 

[Murloc]

I think they are probably worse.

We all get the cashiers that look dumbfounded when you give them odd amounts of money, like $10.50 for a $7.15 bill.

Last week the register at Trader Joes wasn't automatically taking 10% my wine cases, so it took four employees trying to figure out what the amount would be (and I ended up showing them how to figure it out). They were all 'okay, so take off ten cents per dollar, and add that up...'.

Division is surprisingly tough for many people also; my friend couldn't figure out how to divide the gas cost for our camping trip... he said "when the hell do I ever have to divide something?".

I understand divisions because you never practice them and they can be difficult even with every day numbers, but I've never seen a cashier who couldn't do the maths swiftly.

While I often found it annoying I can understand it from a teacher's point of view in a number of situations. If you get it wrong was it an arithmetic error or a procedural one? Did you just cheat and look at someone else's answer and copy it down? Use a calculator on a 'no calculator allowed' test? etc etc

yeah this, it's frustrating if you don't have enough time to complete the test but it makes sense since people should learn from the corrections.

 

[Blackjack200]

pics of the girl?

It took 38 replies? WTF ATOT?

 

[Zenmervolt]

Bah. Wait til it's $7.87, give them a 10, then as they punch it in, say, "here's another $3.12 to make the change a lot easier for you."

I'd give them $3.13, but that's just me.

ZV

 

[exdeath]

I'd give them $3.13, but that's just me.

ZV

Don't you mean $2.87?

 

[ss284]

I know PhDs in math/econ who struggle to calculate a 20% tip. Granted I struggle a bit too after drinking a few glasses of wine.

 

[exdeath]

I know PhDs in math/econ who struggle to calculate a 20% tip. Granted I struggle a bit too after drinking a few glasses of wine.

Again... 10% just shift decimal one place, then double the result.

Rounding ftw also when tipping. Because a 4.94 tip (2.47 x 2) instead of $5 is lame anyway.



Probably trying to do X * 0.20 in their head the way they were taught.

 

[rudeguy]

It took 38 replies? WTF ATOT?

I don't know. ATOT just isn't the same anymore

 

[Dumac]

There is a difference between not being able to crunch numbers in your head (i.e. addition/multiplication of large uglynumbers) and just not understanding basic concepts.

I can accept the former - that is where you could use a calculator.

But the latter? What the hell is wrong with you?

 

[Vdubchaos]

There is a difference between not being able to crunch numbers in your head (i.e. addition/multiplication of large uglynumbers) and just not understanding basic concepts.

I can accept the former - that is where you could use a calculator.

But the latter? What the hell is wrong with you?

Some people are simply not very good at math.

Are you telling me you are good at EVERYTHING?