Addition: 10 + 3 = 13

Subtraction: 10 - 3 = 7

Multiplication: 10 * 3 = 30

Division: 10 / 3 = 3.3333333333333

Modulus: 10 % 3 = 1

Explanation

The addition operator (+) adds numbers together. The subtraction operator (-) subtracts one value from another. Multiplication (*) multiplies two numbers. Division (/) divides one number by another. The modulus operator (%) returns the remainder after division. These operators allow PHP to perform mathematical calculations.