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here comes for the most people a very simple question that I can't understand. How did I calculate the percent of a number?
If I have a variable with the number 1000 stored in it, and I want to calculate what 15,55 % of that number is and store the result in another variable. How? Can someone give me an example?
This should help - http://www.purplemath.com/modules/percntof.htm
As far as code is concerned, what could you write?
number times .1555
shall I do something like this:
If we take 10 percent of 1000.
I don't know if I shall use the % sign? Probably this is totaly wrong :DCode:int result;
int number = 1000;
result = 10 % number;
10 % of 1000 here would be 10*1000/100. % is for finding remainder.
Can you explain this more? What is 'times'?Quote:
Originally Posted by GCDEF
Yes, but if I want 0.65% of 1000?Quote:
Originally Posted by exterminator
0.65*1000/65 is this correct?
Hmm, no math knowledge, no language knowledge... ts ts ts :)Quote:
Originally Posted by Lindberg
He means 1000 * 0.1555 :)
-Andy
>> Yes, but if I want 0.65% of 1000?
>. 0.65*1000/65 is this correct?
No. It would be
Or more conciselyCode:0.65 / 100 * 1000
Code:0.0065 * 1000
ok, I have now came to a conclusion.
So simple it was :) Thanks for all help!Code:double result;
int number = 1000;
char chresult[15];
result = number * 0.15;
No disrespect for Lindberg, who is asking an honest question, but this is a truly pathetic commentary on the school system in Sweden.Quote:
Originally Posted by Lindberg
And I thought that the school system here in the U.S. was pathetic.
Perhaps he is only 7 years old? :-)
Hmm... Are you sure you mean pathetic - or pathologic? ;)Quote:
Originally Posted by MikeAThon
It's nothing wrong with the school system in sweden, i have learned the most mathematic thing in my school. But it is a quite different thing to calculate mathematics in a programming language like c++, especially if you are a beginner.
I'm 30 years old :DQuote:
Originally Posted by Mark Xa
I do not think it says anything about the school where Lindberg has studied. The problem is that the way we do mathematical calculations on paper and the way we write programs for that are often different. In the context of this thread, consider %. In Mathematics, we know that % means percentage, but in C++, it means remained when one integer is divided by another.
Several years back, when I first learnt about computer programming (it was Fortran 77), then I was surprised that there is an upper limit to integer. From Mathematics, I had learnt that there is no upper limit to integer. :-)
Just a few days back, I was writing a program in VB where I had to calculate probability using Binomial distribution. It requires factorial. Using paper and pen I can do calculations in a very short time but my program was failing even though the sample size was as small as 30. I tried integer, long and even currency data type. For very high precision and to store large numbers, currency data type is used in VB. That also did not help. Then I used Sterling approximation to find factorials. That worked for sample size upto 50. Then I did lots of other optimizations and could somehow make it work for sample size of 3,500.
So, this is the problem. The way we do calculations using pen and paper and the way we need to write programs to do mathematical calculations are often different.
Coming the the question that Lindberg asked. This is how you can write program:-
//Declare the variables. I am assuming that the number whose percentage
//is to be calculated does not have fractional parts. Otherwise,
//instead of long, use double.
long lNumber = 0;
double dblPerc = 0;
//Enter the values
lNumber = 1000;
dblPerc = 15.55;
double dblResult = lNumber * dblPerc/100;