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Topic summary · IGCSE handout

Standard Form summary

Standard form a×10na\times10^n with 1≤∣a∣<101\le|a|<10 handles very large or small numbers cleanly.

Files: 20_standard_form_handout.pdf · 20_standard_form_handout_answers.pdf · free public downloads · diagrams in the PDFs

Key learning points

  • Convert by moving the decimal point and counting powers of 10.
  • Multiply: multiply aas and add indices; divide: divide aas and subtract indices; then renormalise.
  • Calculator standard-form mode is useful for checks, not a substitute for method.

Worked example 1 — Convert

Write 4500045000 in standard form.

Working

4.5×1044.5\times10^4

One non-zero digit before the point.

Worked example 2 — Ordinary number

Write 3.2×10−33.2\times10^{-3} ordinarily.

Working

0.00320.0032

Move the point 3 places left.

Worked example 3 — Multiply

(2×103)(3×104)(2\times10^3)(3\times10^4).

Working

6×1076\times10^7

Multiply coefficients; add indices.

Scaffolded Learning Sheet and answers (PDFs)

This page is a short, searchable overview for revision and search engines. Use the Scaffolded Learning Sheet first, then the Answers PDF for a full written solution. The printable PDFs remain the main classroom resource.