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Cambridge / IGCSE • Integers & Rational Numbers

Positive and Negative Numbers

Integers include whole numbers and their negative opposites. Understanding direction on a number line is key.

Learning Objectives

  • Understand integers on a number line
  • Add and subtract positive and negative integers
  • Apply signs rules for multiplication and division

Lesson Explanation

Lesson Content

Moving right on the number line increases value; moving left decreases value. When multiplying two numbers: (+)(+) = +, (-)(-) = +, (+)(-) = -.

💡 Key Takeaway

Take one step at a time, check your working carefully, and keep both sides balanced!

Worked Examples

Example 1

Calculate -5 + 8

  1. Step 1

    Start at -5 on the number line

  2. Step 2

    Move 8 units to the right

  3. Step 3

    Answer: 3

Example 2

Calculate (-4) × (-6)

  1. Step 1

    Both numbers are negative (same signs)

  2. Step 2

    Negative times negative equals positive

  3. Step 3

    Answer: 24

Visual Method

Balance Every Step

Mathematics becomes much clearer when you can see the structure behind equations.

Watch Video Explanation

Practice Questions

Try solving each question on paper first. Tap below to check a helpful hint or solution!

Question 1

Calculate -7 - 4

Show Hint / Solution 💡

Start at -7 and move 4 units left.

Question 2

Calculate 15 ÷ (-3)

Show Hint / Solution 💡

Positive divided by negative equals negative.

Lesson Summary

What to Remember

Same signs make positive, different signs make negative!

Download Lesson Notes ↓