lesson
Calculate the coefficient and scale
1 · Learn
Multiply standard-form numbers by multiplying coefficients and adding powers of ten, then normalise the coefficient. Division divides coefficients and subtracts exponents. Addition first needs matching powers.
Check magnitude with an estimate. A coefficient outside the interval from 1 up to but not including 10 needs an adjusted exponent.
2 · Worked example
(3 × 10⁴)(4 × 10³) = 12 × 10⁷ = 1.2 × 10⁸.
3 · Your turn
Calculate (6 × 10⁵) / (2 × 10²).
Check your answer
3 × 10³.
4 · Apply your learning
Explain why 3 × 10⁴ + 4 × 10³ equals 3.4 × 10⁴, not 7 × 10⁷.
Adult guidance and safety
Require reasoning and a check. Provide accurate graphs, construction instruments and varied practice. Annual KS3 allocation is proposed; do not treat these short models as a complete assessed programme.
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