Powers & Roots

MathematicsAQAEdexcelGCSEUnit: Number
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The basics

The Power of Powers

The Power of Powers

When you calculate the area of a square room that's 5m × 5m, you write 5² = 25m². When finding the volume of a cube box that's 3m × 3m × 3m, you write 3³ = 27m³. Powers (indices) are a shorthand for repeated multiplication, while roots help us work backwards - if a square has area 64m², its side length is √64 = 8m.
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Common Mistakes to Avoid

❌ Wrong: 2³ = 6 ✅ Right: 2³ = 8

Powers mean multiply, not add: 2×2×2 not 2×3

❌ Wrong: √9 = ±3 ✅ Right: √9 = 3

Square root symbol means positive root only

❌ Wrong: (-2)² = -4 ✅ Right: (-2)² = 4

Negative × negative = positive

❌ Wrong: -4² = 16 ✅ Right: -4² = -16

Without brackets: square first, then apply negative

Now try it yourself

Quiz · Question 1 of 15

What is the value of 2⁻³?

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