Though the expression called 100+200=300 was displayed on the screen in the foregoing paragraph
The numerical value called 100,200,300 was arranged directly at that time.
In a word, Man was previously calculating the part of the answer called 300.

However, there is with this no computer-aided meaning.
Such a calculation should make the computer put it.

In C language, only because the expression is described to calculate, it is settled.
The following program is an example of making the computer put the calculation of 100+200.

 int main(void)  
{
	100+200;
}

[ The   computer is obstinate and obedient   ].
The computer is obstinate and obedient in this manner.
In short, though all the given instructions are obediently executed on the street
Besides, it has obstinacy of not giving the full monty.
Though it is natural to display the result when calculating from man
The computer doesn't have such consideration at all.

Actually, it is also possible to pass the expression, and to convert the numerical result of the expression into the figure.
The following program is an example that calculates 100+200 and displays.

 
#include <stdio.h> 

int main(void)  
{
	printf("%d\n",100+200);  
	return 0;
}

300

Of course, other calculations are also possible though it added in the preceding clause (addition).
A basic operator of C language is as shown in the following table.

Sign in C language	Sign in mathematics	Function
+	+	Addition(addition)
-	-	Subtraction(subtraction)
*	×	Multiplication(multiplication)
/	÷	Division(dividing calculation)
%	…	Surplus calculation(The dividing calculation too much. )

I think that I notice a sign different from mathematics might used when this table is seen.
Because there are neither × nor ÷ in the sign expressible with the keyboard of a general computer
It doesn't limit to C language, and another sign is used in a lot of programming languages.

The usage of the operator is quite the same as mathematics.
The following program is an example that uses the operator introduces here in general.

 
#include <stdio.h> 

int main(void)  
{
	printf("%d\n",10 + 3);  
	printf("%d\n",10 - 3);  
	printf("%d\n",10 * 3);  
	printf("%d\n",10 / 3);  
	printf("%d\n",10 % 3);  
	return 0;
}

13
7
30
3
1

The result of the integer calculation becomes not the half-adjust but a round-down.
Because when you reversely calculate the number quotient × divided when rounding it off
From ....former.. drinking.. number to it is as a result because contradiction of largeness is caused that is [wari]

[   Bargain calculator and high-level calculator   ]
Actually, this calculation is an easy method of distinguishing a bargain calculator and a high-level calculator.
You also : with a calculator on hand Calculate with 10÷3×3.
Though it was displayed in the high-level calculator that the author has as ten
In the calculator in the hundred-yen store It was displayed as 9.9999999.
Seem to pursue the calculation on the way and to display it accurately in a high-level calculator.

 
#include <stdio.h> 

int main(void) 
{         printf("%d\n",(1 + 100) * 100 / 2);  
   return 0; 
}

5050