User Input & Standard Arithmetic Operations

Interactive computing requires reading data dynamically from users and applying arithmetic transformations according to mathematical precedence rules.

1. Accepting Input (INPUT)

The INPUT statement reads data from an external input device (e.g. keyboard) and stores it in a declared variable:

DECLARE StudentAge : INTEGER
OUTPUT "Please enter your age: "
INPUT StudentAge

2. Standard Arithmetic Operators

Cambridge pseudocode supports the five fundamental mathematical operators:

3. Operator Precedence (BODMAS / PEMDAS)

When an expression contains multiple operators, operations are executed in a strict hierarchy:

1. Brackets (...): Expressions inside parentheses evaluate first.
2. Exponents ^: Evaluated next.
3. Multiplication * and Division /: Evaluated left to right.
4. Addition + and Subtraction -: Evaluated left to right.

// Without parentheses (Multiplication first):
Result <- 10 + 5 * 2       // 10 + 10 = 20

// With parentheses:
Result <- (10 + 5) * 2     // 15 * 2 = 30

4. Cambridge Relational Operators

Relational operators compare two values and evaluate to a BOOLEAN result (TRUE or FALSE):