Year 8 · Maths · Indices and standard form · Lesson 3
Standard form: small numbers
Write small numbers in standard form using negative powers of 10, convert back, order them, and calculate with them.

28-minute video lesson
Teaching, worked examples and 20 practice questions solved step by step.
Watch free for a monthWhat your child will learn
- Understand negative powers of 10
- Write small numbers in standard form
- Convert small numbers back to ordinary numbers
- Order numbers in standard form
- Multiply and divide numbers in standard form
The method
- The first number must be at least 1 and less than 10.
- Count how many places the decimal point moves.
- Number less than 1: negative power of 10.
- To convert back, move the point left that many places.
Key words: standard form, negative power, power of 10, decimal, place value.
Worked examples
The first three practice questions from the lesson, with every step.
Question 1
Write 0.04 in standard form.
- Step 1: First number: 4
- Step 2: 4 to 0.04: the point moves 2 places left
- Step 3: 0.04 = 4 × 10⁻²
Answer: 4 × 10⁻²
Question 2
Write 0.0062 in standard form.
- Step 1: First number: 6.2
- Step 2: 6.2 to 0.0062: the point moves 3 places left
- Step 3: 0.0062 = 6.2 × 10⁻³
Answer: 6.2 × 10⁻³
Question 3
Write 0.000315 in standard form.
- Step 1: First number: 3.15
- Step 2: 3.15 to 0.000315: the point moves 4 places left
- Step 3: 0.000315 = 3.15 × 10⁻⁴
Answer: 3.15 × 10⁻⁴