Mathematical Operators

At its core, a computer is a powerful calculator. To perform calculations, we use mathematical operators. You know most of them from school, but in programming, they have specific rules, especially regarding data types.

Mathematical Operator

A symbol or word that tells the compiler/interpreter to perform a specific mathematical operation on given values (operands).

Basic Operators

Here is the set of tools you will find in almost every programming language (C++, Java, Python, JS).

Cecha	Symbol	Name
+	Addition	5 + 2
-	Subtraction	5 - 2
*	Multiplication	5 * 2
/	Division	5 / 2
%	Modulo (Remainder)	5 % 2

The Trap: Integer vs Floating-Point Division

This is a common cause of errors in coding tasks. The result of division depends on the data types of the numbers.

Division in C++ / Java

If you divide two integers (int), the result will always be truncated to an integer. Example: 5 / 2 results in 2, not 2.5! To get 2.5, at least one number must be a double/float (e.g., 5.0 / 2).

Increment and Decrement

Used to quickly increase or decrease a value by 1. Very popular in loops.

++ (Increment): increases by 1
-- (Decrement): decreases by 1

Pre- vs Post-increment

`++i` (pre): increments first, then returns the value. `i++` (post): returns the old value first, then increments. This can lead to very subtle logic bugs.

Example: Modulo in Practice

The % (modulo) operator is extremely useful, for example, for checking if a number is even:

cpp

int number = 10;
if (number % 2 == 0) {
    // Number is even
}

Pro Tips

Operator Precedence

Programs follow mathematical order of operations (multiplication before addition). Always use parentheses `()` to ensure calculations happen as intended. This also improves code readability.

Calculation Checklist

Rules for safe calculations

0/4

Quiz: Check Your Knowledge

What is the result of 7 % 3 in most programming languages?

Operator Hierarchy (Mermaid)

What's Next?

Learn about Assignment Operators (e.g., +=, *=) that shorten your code.
Check out Comparison Operators (e.g., ==, !=), essential for conditional statements.
Read about the Math Class (in Java/JS) or the <cmath> header (in C++), which allow for power and square root functions.
Practice INF.04-style tasks requiring calculations with integer and floating-point types.

Mathematical Operators

Mathematical Operator

A symbol or word that tells the compiler/interpreter to perform a specific mathematical operation on given values (operands).

Cecha

Symbol

Name

Addition

5 + 2

Subtraction

5 - 2

Multiplication

5 * 2

Division

5 / 2

Modulo (Remainder)

5 % 2

The Trap: Integer vs Floating-Point Division

This is a common cause of errors in coding tasks. The result of division depends on the data types of the numbers.

Division in C++ / Java

If you divide two integers (int), the result will always be truncated to an integer. Example: 5 / 2 results in 2, not 2.5! To get 2.5, at least one number must be a double/float (e.g., 5.0 / 2).

Increment and Decrement

Used to quickly increase or decrease a value by 1. Very popular in loops.

++ (Increment): increases by 1

-- (Decrement): decreases by 1

Pre- vs Post-increment

`++i` (pre): increments first, then returns the value. `i++` (post): returns the old value first, then increments. This can lead to very subtle logic bugs.

What's Next?

Learn about Assignment Operators (e.g., +=, *=) that shorten your code.

Check out Comparison Operators (e.g., ==, !=), essential for conditional statements.

Read about the Math Class (in Java/JS) or the <cmath> header (in C++), which allow for power and square root functions.

Practice INF.04-style tasks requiring calculations with integer and floating-point types.

Mathematical Operators: The Foundation of Computing

Mathematical Operators

Basic Operators

The Trap: Integer vs Floating-Point Division

Increment and Decrement

Example: Modulo in Practice

Pro Tips

Calculation Checklist

Rules for safe calculations

Quiz: Check Your Knowledge

Operator Hierarchy (Mermaid)

What's Next?

You might also like

Relational and Logical Operators: How to Compare Data?

Conditional Operator: Short-hand if-else in one line

Reserved Keywords: List of Key Terms in IT

Mathematical Operators: The Foundation of Computing

Mathematical Operators

Basic Operators

The Trap: Integer vs Floating-Point Division

Increment and Decrement

Example: Modulo in Practice

Pro Tips

Calculation Checklist

Rules for safe calculations

Quiz: Check Your Knowledge

Operator Hierarchy (Mermaid)

What's Next?

You might also like

Relational and Logical Operators: How to Compare Data?

Conditional Operator: Short-hand if-else in one line

Reserved Keywords: List of Key Terms in IT