This key facts covers Standard Form Rules within Standard Form for GCSE Mathematics. Revise Standard Form in Number for GCSE Mathematics with 14 exam-style questions and 22 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 3 of 15 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Standard Form Rules
| Type | Standard Form | Example | Ordinary Number |
|---|---|---|---|
| Large Numbers | a × 10ⁿ (n positive) | 3.5 × 10⁶ | 3,500,000 |
| Small Numbers | a × 10⁻ⁿ (n negative) | 2.7 × 10⁻⁴ | 0.00027 |
| Numbers 1-10 | a × 10⁰ | 5.2 × 10⁰ | 5.2 |
| Invalid Form | a < 1 or a ≥ 10 | 15 × 10³ ❌ | Should be 1.5 × 10⁴ |
Practice questions for Standard Form
Which of these numbers is written in standard form?
Explain why standard form is useful for writing very large or very small numbers.
Quick recall flashcards
What is Standard Form?
A number written as a × 10ⁿ
Where:
• 1 ≤ a < 10 (at least 1, less than 10)
• n is an integer (whole number)
Example: 3.5 × 10⁴
Converting TO Standard Form
1. Move decimal to make 1 ≤ a < 10
2. Count places moved
3. Large (left) → positive power
4. Small (right) → negative power
780,000 → 7.8 × 10⁵