Standard Form

This lesson covers writing numbers in standard form (also called scientific notation), converting between standard form and ordinary numbers, performing calculations in standard form, and ordering numbers given in standard form. Standard form is a key Number topic in the Edexcel GCSE Mathematics (1MA1) specification.

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Key Vocabulary

Term	Meaning
Standard form	A way of writing very large or very small numbers as A × 10^n
Ordinary number	A number written in the normal way, e.g. 45,000
Significant figures	The meaningful digits in a number

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What Is Standard Form?

A number in standard form is written as:

A × 10^n

where:

• 1 ≤ A < 10 (A is at least 1 but less than 10)
• n is an integer (positive, negative or zero)

Examples

Ordinary number	Standard form
45,000	4.5 × 10⁴
3,200,000	3.2 × 10⁶
0.00072	7.2 × 10⁻⁴
0.0000009	9 × 10⁻⁷
8.1	8.1 × 10⁰

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Converting from Ordinary Numbers to Standard Form