# Explain why scientists use standard SI units and prefixes when sharing measurements with other scientists around the world.

> Edexcel GCSE Physics (1PH0) — 1.1 Key concepts of physics · Explain · 4 marks

## Mark scheme (4 marks)

1. Using standard SI units means all scientists use the same units for the same quantities
2. This allows measurements to be compared or reproduced without confusion or error
3. Prefixes such as kilo, mega or milli are used to express very large or very small quantities
4. This makes numbers easier to work with / write, avoiding very long strings of zeros

## Key terms

- [SI units](https://www.gradenine.co.uk/glossary/si-units)
- [prefixes](https://www.gradenine.co.uk/glossary/prefixes)

## Related

- [Revision notes for Edexcel GCSE Physics (1PH0)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-scientists-use-standard-si-41806f13) · Published by Druglandscape Ltd.