Maths for Scientists
Published 26 March 2026
Master rearranging equations, converting units like cm³ to dm³, and avoiding common Chemistry and Physics maths mistakes in GCSE Science.
Why maths matters in GCSE Science
Many students understand the science but drop marks on the maths. In Physics and Chemistry especially, one unit error or rearranging mistake can lose the whole calculation.
The good news is that most of these mistakes are predictable, which means they are fixable.
- Read the formula carefully
- Check whether unit conversion is needed first
- Write working clearly so you can spot mistakes
Rearranging equations
Do not try to do everything in your head. Write the formula first, substitute values second, and rearrange only one step at a time.
For example, if density = mass ÷ volume, then volume = mass ÷ density. Students often flip the wrong numbers because they rush.
- Start with the formula exactly as given
- Move one term at a time
- Check whether the final answer makes sense
Converting units like cm³ to dm³
Volume conversions are a classic GCSE trap. Because 1 dm = 10 cm, it does not mean 1 dm³ = 10 cm³. In fact, 1 dm³ = 1000 cm³.
That means to convert from cm³ to dm³, divide by 1000. To convert from dm³ to cm³, multiply by 1000.
- 250 cm³ = 0.250 dm³
- 0.5 dm³ = 500 cm³
- Always check the power on the unit
Common mistakes in Chemistry and Physics
In Chemistry, students often forget to convert cm³ to dm³ before using concentration calculations. In Physics, students may use the right equation but leave the unit in centimetres instead of metres.
A quick unit check before calculating can save a lot of marks.
- cm to m: divide by 100
- cm³ to dm³: divide by 1000
- Round only at the end unless the question tells you otherwise
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