Arithmetic Operators
Last Updated: Jan 2026
Arithmetic operators are used in C to perform mathematical calculations on values and variables. The main arithmetic operators are:
+ Addition
- Subtraction
* Multiplication
/ Division
% Modulus / Remainder
1. Addition +
The + operator adds two values.
int a = 10;
int b = 5;
int result = a + b;
printf("%d", result); // 15
2. Subtraction -
The - operator subtracts the right-hand value from the left-hand value.
int a = 10;
int b = 5;
int result = a - b;
printf("%d", result); // 5
3. Multiplication *
The * operator is used for multiplication.
int a = 10;
int b = 5;
int result = a * b;
printf("%d", result); // 50
4. Division /
The / operator divides one value by another.
int a = 20;
int b = 5;
int result = a / b;
printf("%d", result); // 4
Important: Integer Division
This is one of the most important concepts in C. If both operands are integers:
int result = 10 / 3;
The mathematical answer is:
3.333333...
But C gives:
3
because both operands are int. The decimal part is discarded. But:
float result = 10.0 / 3;
printf("%f", result);
Output:
3.333333
Because 10.0 is a floating-point value.
5. Modulus %
The % operator returns the remainder after integer division.
int result = 17 % 5;
Think:
17 ÷ 5
5 x 3 = 15
17 - 15 = 2
Therefore:
17 % 5 = 2
Arithmetic Operators with Variables
int a = 20;
int b = 6;
printf("%d\n", a + b);
printf("%d\n", a - b);
printf("%d\n", a * b);
printf("%d\n", a / b);
printf("%d\n", a % b);
Output:
26
14
120
3
2
Notice:
20 / 6 = 3
20 % 6 = 2
The division gives the quotient and modulus gives the remainder.
