Scientific notation

Definition

Scientific notation writes a very large or very small number as a number between 1 and 10 multiplied by a power of 10. The power is positive for large numbers and negative for numbers smaller than 1.

Worked example

52 000 000 = 5.2 × 10⁷, because the decimal comma moves 7 places to the left.

0.000 45 = 4.5 × 10⁻⁴: the decimal comma moves 4 places to the right, so the power is negative.

(4 × 10³) × (3 × 10⁵) = 12 × 10⁸ = 1.2 × 10⁹.

Where it appears in the exam

Scientific notation is part of the numbers section of CAPS Grade 9 Mathematics and appears in school tests and the end-of-year exam.

Step-by-step method

1. Place the decimal comma after the first non-zero digit.
2. Count how many places it moved.
3. Use a positive power of 10 for large numbers and a negative power for small numbers.
4. Check that the first number is between 1 and 10.

Common mistake

Writing 12 × 10⁸ as a final answer: in scientific notation the first number must be less than 10.

Related numbers terms

• Irrational number

Frequently asked questions

What does scientific notation mean in Grade 9 Maths?

Scientific notation writes a very large or very small number as a number between 1 and 10 multiplied by a power of 10. The power is positive for large numbers and negative for numbers smaller than 1.

When do you learn about scientific notation?

Scientific notation is taught in the numbers section of CAPS Grade 9 Mathematics and is used again in Grades 10 to 12.

How do I practise questions involving scientific notation?

Snap a question that uses scientific notation into Snap&Learn with your grade set to Grade 9, or work through the Grade 9 topic guide and practice papers.