Directed numbers are positive and negative numbers, including integers and decimals. They appear in IGCSE Maths and many secondary curricula. This guide covers the rules and examples for Singapore students.

What are directed numbers?

Directed numbers include positive numbers (e.g. 3, 0.5), negative numbers (e.g. -2, -0.1), and zero. On a number line, positive is usually to the right and negative to the left. You use them in addition, subtraction, multiplication, division, and in algebra (e.g. solving equations, coordinates). In real life they appear in temperatures, bank balances, and positions above or below a reference point.

Rules for directed numbers

Addition: Adding a negative is like subtracting (e.g. 5 + (-3) = 5 - 3 = 2). Subtraction: Subtracting a negative is like adding (e.g. 5 - (-3) = 5 + 3 = 8). Multiplication and division: Same signs give a positive result (e.g. (-2) × (-3) = 6); different signs give a negative result (e.g. (-2) × 3 = -6). Learn these rules and practise with mixed operations so you can apply them quickly in algebra and word problems.

Why directed numbers matter for IGCSE

IGCSE Maths uses directed numbers in algebra (e.g. solving linear equations, simplifying expressions), coordinates (positive and negative x and y), and real-life contexts (profit and loss, temperature, height above/below sea level). Practise with past papers and make sure you are confident before the exam. Combine with other IGCSE resources and tuition for full preparation.

Practice tips for directed numbers

Use a number line to see that subtracting a negative moves you right (add). For multiplication and division, remember same sign positive, different sign negative, and practise with many examples. Do mixed operations (e.g. -3 + 2 x (-4)) so you apply the rules and BIDMAS correctly. Singapore students can use IGCSE past papers and IGCSE Maths tuition on Tutopiya to practise directed numbers in exam-style questions.

Next steps

For IGCSE Maths tuition in Singapore, book a free trial with Tutopiya. Use the Tutopiya learning platform for live lessons and past paper practice.