Math

K

KQX

Vault Senior Citizen
I used to be pretty good at math. Then in freshman year of college I got into integral calculus and I was very annoyed by it. It wasn't so much that I didn't understand it, I did, but I saw that in order to do well I needed to practice and do homework a lot. Since I knew I didn't want math as a major, I never took another math class after that one.

Another problem that I have is that I'm addicted to the calculator. I would always use it, even with simple stuff I probably could have done in my head. Eventually, my brain got pretty lazy with math and even with simple stuff I didn't trust my own calculations (really, the Party wouldn't have to work very hard to convince me that 2+2=5)

Anyway, here I am now, working full time as an options trader, which basically means that I'm surrounded by math. And I've realized that the deeper I go into this profession, the more I need to develop the ability to simply see math answers in front of me as opposed to always reaching for the calculator. I especially need to be able to work with dividing decimal numbers and getting decimals from fractions.

So I'm wondering if anyone is in a similar situation or has some advice on developing this skill. Any helpful tips/resources?

I found this one website helpful when it comes to fractions/decimals. Useful stuff to know for anyone, I'd say.
 
Yes, the calculator was removed from my hands when I started college. However, Im improved instantly, because it forced me to actually think. I had three compulsory maths courses (plus one statistics course), and I ended up getting the top grade in all 3, including best in class in the third course.

Just like anything else, it's about time spent learning it. What helped me, IIRC, was checking examples and solving problems. You don't really get a lot from just reading it, like you would say, an economics course or something.
 
Reiterating what has been said, it is the time spent using it that is most important, as opposed to just reading about it.

One must practise practise practise.

However, worked examples are incredibly useful.

Personally, I also let my mathematics slip as I am unwilling to put in the work and have a natural lack of talent for it anyway, which bothers me a bit. I am almost totally reliant on the calculator for arithmetic. Maybe I should practise more often than I do, and I believe that there are numerous little tricks that can be used, many of which should be on the net. I wonder how many good maths games have been created to keep things interesting?

The other day I was asking one of the top biochemistry researchers in Australia if I might get kneecapped by my weak maths, and was reminded that for real mathematics, one can collaborate with experts, such as with a professional mathematician to assist in the design of a new imaging technique.
 
Hello KQX

I'm a high school math teacher that teaches Algebra I and Algebra II.

I've taken Linear Algebra, Calculus 1, 2, 3 and Differential Equations in college.

It appears that what you need for your profession is what we call 'number sense'. The way positive and negative numbers work together in the basic operations (addition, subtraction, multiplication, and division).

I strongly recommend learning your multiplication tables by heart (1-15 x 1-15). Any combination of these numbers is important.

For Example:
7x8 = 56
12x12 = 144
etc.

This may seem simplistic, but it will reduce reaching for the 'magic box' (i.e. calculator) greatly.

Another thing is learning many of the basic fractions in reduced form:

1/8 = 0.125
1/4 = 0.25
1/3 = 0.33333....
1/2 = 0.5
2/3 = 0.66666....
3/4 = 0.75

There is no need to worry about 2/4 or 4/6 etc. since they reduce to a more basic form. (the key is you need to know how to reduce them!)

Finally, if you need to convert a decimal number into a fraction, one method is to place the decimal number over a power of 10, depending on the number of decimal places you have, and then removing the decimal.

For example:

0.54 = 54/100
and 54/100 then reduces to 27/50

0.16 = 16/100
and 16/100 then reduces to 4/25

0.7 = 7/10
and 7/10 cannot be reduced.

Hopefully this can at least give you a starting point. If you have some concrete examples of what you're dealing with we may be able to help more.

-Quaid
 
whoa a math teacher - this place keeps getting better and better :P

never used calculators in school/college
Horrible creatures i avoid them... :P
 
metalboss44 said:
ugh, math...
Click to expand...

Hah, I identify with that sentiment; however, I rally do find fascination with complex mathematics... Theoretical math and what have you.
 
You know that happened to me too, after I received a calculator I just got lazy. Before using it for some time I would calculate stuff like what change I'm supposed to get faster than the vendor who was using a calculator. After that I found myself questioning my mental calculus and I decided to stop using the calculator or at least keep it for emergency situations. I found the barter system in FO to be very educational, when the goods don't even out value-wise somebody needs to fork over some hard currency. It's exercise in a fun way...
 
Quaid said:
Hello KQX

I'm a high school math teacher that teaches Algebra I and Algebra II.

I've taken Linear Algebra, Calculus 1, 2, 3 and Differential Equations in college.

It appears that what you need for your profession is what we call 'number sense'. The way positive and negative numbers word together in the basic operations (addition, subtraction, multiplication, and division).

I strongly recommend learning your multiplication tables by heart (1-15 x 1-15). Any combination of these numbers is important.

For Example:
7x8 = 56
12x12 = 144
etc.

This may seem simplistic, but it will reduce reaching for the 'magic box' (i.e. calculator) greatly.

Another thing is learning many of the basic fractions in reduced form:

1/8 = 0.125
1/4 = 0.25
1/3 = 0.33333....
1/2 = 0.5
2/3 = 0.66666....
3/4 = 0.75

There is no need to worry about 2/4 or 4/6 etc. since they reduce to a more basic form. (the key is you need to know how to reduce them!)

Finally, if you need to convert a decimal number into a fraction, one method is to place the decimal number over a power of 10, depending on the number of decimal places you have, and then removing the decimal.

For example:

0.54 = 54/100
and 54/100 then reduces to 27/50

0.16 = 16/100
and 16/100 then reduces to 4/25

0.7 = 7/10
and 7/10 cannot be reduced.

Hopefully this can at least give you a starting point. If you have some concrete examples of what you're dealing with we may be able to help more.

-Quaid
Click to expand...

I thought this was primary school stuff.

Anyway, I once heard a nice joke (originating from The Economist or something like that).
Our Macroeconomics I teacher said:
In the seventies, students were given this task: The saw-mill buys one tree for 10$. The lumberjack cuts ten of them in one day and the cost of cutting and transporting one tree to the saw-mill is 7$. How much will he earn at the end of the day?

In the eighties, the task changed. Lumberjack cuts ten trees per day. Ten trees are bought for 100$ at the saw-mill and it costs 70$ to transport and cut them. How much will the lumberjack earn at the end of the day?

In the nineties, the task changed again. Lumberjack cuts ten trees per day. Ten trees are bought for 100$ at the saw-mill and it costs 70$ to transport and cut them. The lumberjack earns 30$. How much will the lumberjack earn at the end of the day?

Now, the task changed totally. Lumberjack cuts ten trees per day. Ten trees are bought for 100$ at the saw-mill and it costs 70$ to transport and cut them and he earns 30$. Write an essay on the topic of "How do the birds and flowers feel".
Click to expand...
 
Karel said:
I thought this was primary school stuff.
Click to expand...
You'd be surprised at how many high school students don't know their multiplication tables and shudder at the sight of fractions due to their reliance on the magic box.

Also, the OP appeared to request this level of mathematics. I simply gave my background before answering his post. I didn't mean to imply I was discussing Algebra or Calculus. :wink:
 
Quaid said:
You'd be surprised at how many high school students don't know their multiplication tables and shudder at the sight of fractions due to their reliance on the magic box.
Click to expand...

Perhaps especially so the
womenhc9.jpg


(Neither can I, but that's just because I don't want to. Carry on.)
 
Karel said:
Our Macroeconomics I teacher said:
In the seventies, students were given this task: The saw-mill buys one tree for 10$. The lumberjack cuts ten of them in one day and the cost of cutting and transporting one tree to the saw-mill is 7$. How much will he earn at the end of the day?

In the eighties, the task changed. Lumberjack cuts ten trees per day. Ten trees are bought for 100$ at the saw-mill and it costs 70$ to transport and cut them. How much will the lumberjack earn at the end of the day?

In the nineties, the task changed again. Lumberjack cuts ten trees per day. Ten trees are bought for 100$ at the saw-mill and it costs 70$ to transport and cut them. The lumberjack earns 30$. How much will the lumberjack earn at the end of the day?

Now, the task changed totally. Lumberjack cuts ten trees per day. Ten trees are bought for 100$ at the saw-mill and it costs 70$ to transport and cut them and he earns 30$. Write an essay on the topic of "How do the birds and flowers feel".
Click to expand...
Click to expand...

The lumberjack earns what his boss pays him, I have no knowledge on lumberjack wage rates in the US :crazy:
 
Quaid said:
Karel said:
I thought this was primary school stuff.
Click to expand...
You'd be surprised at how many high school students don't know their multiplication tables and shudder at the sight of fractions due to their reliance on the magic box.
Click to expand...

No, I won't be surprised, I "work" as a maths private tutor, but this seemed to be relatively basic and something you would consider "standard" (multiplication, not fractions).

Calculators are evil, I once taught a kid who would use it to calculate something like time of travel of a plane, which was 4/3 hours and read the result as one. Another time, 1/3 was just 1.33333333 and perfectly precise. Thanks god you have to pass exams to get to high school and university (college) - no "No Child Left Behind" here, but we are getting there soon.

If it's only about revising fractions, some time ago I created a simple tool to generate hundreds of (reducible) fractions because I once run out of exercises while teaching one kid (not that it would help, but I gave the web address to parents and as usual, they were very keen to help their child to master math :mrgreen: ). Unfortunately, I don't know about any such generator for linear / quadratic equations (it won't be hard to write one, but the equations must be solvable, so you have to generate them, calculate and remove those without solution - new book is cheaper).
 
I'm happy to say I do know the very basics such as the multiplication table and fractions. I do need a little more work with decimals it seems.

If you have some concrete examples of what you're dealing with we may be able to help more.
Click to expand...

OK, I'll give a specific situation that happened recently. Hmm, I'm going to go into unnecessary detail here, but It'll help me think while I write.

So I trade options, which are contracts to buy/sell something at a certain price at a certain point in the future. These contracts have different prices associated with them. Depending on how the market moves, these different contracts have varying levels of sensitivity to the percent of market volatility. This sensitivity is called vega, and it's expressed in terms of a decimal. A vega of 0.2 means that if volatility changes by 1%, the price of the option changes by 0.2

1% and 0.2 are big numbers considering that I have to think of options prices and volatility in terms of hundredths. More specifically, I need to see how much I need to add/subtract from the vega number so that the options price would change by 0.01 (or even 0.005 or .03...) So I set up a proportion. If 1% changes the price by 0.2, then how much to change the price by 0.01?

x= 0.01 / 0.2

So when I saw this, I thought it's calculator time. But then I'm trying to avoid that. So what I did is I thought of the division as a fraction.

x= 1/20

Since I know that 1/10 is 0.1, I can deduce that 1/20 is half of it, meaning that the answer is 0.05.

So yeah great, I managed to find the answer, but this is too slow and step by step. So I realized that what I need to be able to do is to look at the vega and be able to instantly see what is the reciprocal of it multiplied by 100.

So if I see 0.2, i need to think 1/20 and know that it's 0.05
0.5 -> 1/50= 0.02
0.3 -> 1/30= 0.03333..

So to do these, memorizing decimals of halves to at least tenths is absolutely necessary. But I'd like to be able to slightly more complicated calculations like 1/68 and know the decimals without just approximating that it's close to 1/70 (0.014).
 
Ugh, calculus. Forget Hitler; Leibniz was the biggest criminal in history. (Still a German, though; go figure.)

High school-level calculus was okay for me, except that I graduated from math with a 4 (where 1 = best and 5 = fail) because I misunderstood the problem I got on the exam, but that had nothing to do with calculus anyway. Once I got to university, thoguh, the teachers set a hellish pace that I absolutely couldn't and didn't want to keep up with. I dropped out after the first semester because of it, having passed all the other subjects (which included things like linear algebra and discrete mathematics). This isn't actually that big of a deal here because there's no tuition in public schools (at least not yet), and a lot of students just re-take the entrance exams.

However, even though I went to another school that was less demanding in the maths department, it still took me three semesters to pass their calculus course. There was supposed to be a big exam after that, but when I'd take it was up to me, which means I kept putting it off until the last possible moment. That took about three years, until I had nowhere to run if I wanted to finish my bachelor's studies. So one day this April I started reading the textbooks again and practicing, and after about a month I passed Teh Exam of Doom with a 2 (where 1 = best and 4 = fail). In the end, it took less effort than some other Teh Exams of Supposedly Lesser Doom, actually.

So yeah. Practice.

But on the other hand, fuck maths.

In the pancreas.
 
Hehe, good one Luke. Seriously though, women are usually better at maths than men in school. How this relates to fellatio I'm not sure.
 
The Overseer said:
Seriously though, women are usually better at maths than men in school.
Click to expand...
euhm, no.

not at all. woman are better at languages, men are better at math.

might be that this isnt so for scandinavians due to brainfreeze thanks to their harsh winters, but still, i'd be very much surprised if this was true.
 
I thought that on average males were innately better at maths/visual-spatial, and females better at languages/verbal, but the girls generally outperform the boys in school almost across the board, for whatever reason. /ignorance
 
thats because girls focus on friendship dynamics and keeping huge lists of who likes who and who hates who in memory while boys simply argue over who is going to be the quarterback.

just imo of course :)
 
You must log in or register to reply here.
Back
Top