Maths questions
Don't forget to take a ruler and calculator into the exam.
Maths questions often start with command words like 'Calculate...''Determine...', 'Estimate...' and 'Measure...'. They will then include blank space for you to show your working.
When an answer to a maths question is marked:
- full marks are given for the right answer (but it is very important to show your working, so you can check your answer and so that, if you make a small slip, you can still get marks for your working)
- marks may be given for working, including substitution and rearrangement
- 'errors carried forward' are worked through to give credit for later working
Errors are carried forward if a later working depends on an earlier answer. You could still get marks if your working is correct but you use the incorrect earlier answer.
If your answer has many decimal places or figures, make sure you give it to an appropriate number of decimal places or significant figures. You may be asked to give units. This may earn you an additional mark, so don’t forget to check whether you need to do this.
Maths questions might ask you to plot or complete a graph or table. When you draw a graph, make sure you:
- plot each point accurately
- draw a best fit straight line or curve, where appropriate
You may be given a grid with axes labelled and scales already given. Sometimes you may be given an empty grid for you to supply your own axes. When you do this:
- put the independent variable on the x-axis and the dependent variable on the y-axis
- choose even scales and make sure that the points cover at least half the given grid
- label the axes with their quantity and unit, eg time (s)
Learn maths skills with Dr Alex Lathbridge
Listen to the full series on BBC Sounds.
Brush up on the maths you need for your exam - percentages, averages and converting units.
Sample question 1 - Foundation
Question
Magnesium reacts with oxygen:
2Mg + O2 → 2MgO
Calculate the maximum mass of magnesium oxide that can be formed from 4.8 g of magnesium.
(Relative atomic mass of Mg = 24; relative formula mass of MgO = 40)
[2 marks]
This question has been written by a Bitesize consultant as a suggestion to the type of question that may appear in an exam paper.
- 24 g of Mg produces 40 g of MgO [1 mark]
- so 4.8 g of Mg produces 40 × (4.8 ÷ 24) = 8 g [1 mark]
Sample question 2 - Foundation
Question
Solder is an alloy of tin and lead.
A sample of a solder was made by mixing 22.5 g of lead with 15.0 g of tin.
Calculate the percentage of tin in this solder.
[2 marks]
Edexcel question courtesy of Pearson Education Ltd.
- % tin = \(\frac{15.0}{(15.0 + 22.5)}\) × 100 [1 mark]
- = 40.0% [1 mark]
Sample question 3 - Higher
Question
Lead nitrate solution mixed with sodium sulfate solution forms lead sulfate as a precipitate.
Pb(NO3)2 + Na2SO4 → PbSO4 + 2NaNO3
The theoretical yield of lead sulfate for this reaction was 2.85 g.
The actual yield of lead sulfate obtained was 2.53 g.
Calculate the percentage yield of lead sulfate in this experiment.
Give your answer to two significant figures.
[3 marks]
Edexcel question courtesy of Pearson Education Ltd.
- % yield = \(\frac{2.53}{2.85}\) × 100 [1 mark]
- = 88.8% [1 mark]
- = 89% to two significant figures [1 mark]
Sample question 4 - Higher
Question
50 cm3 of potassium hydroxide solution of concentration 40 g dm-3 is needed for an experiment.
Calculate the mass of potassium hydroxide that must be dissolved in water to make 50 cm3 of solution of this concentration.
[2 marks]
Edexcel question courtesy of Pearson Education Ltd.
- mass = 40 × \(\frac{50}{100}\) [1 mark]
- = 2 g [1 mark]
