Maths questions

Maths questions often start with the command words 'calculate' or 'determine'. They will then have a blank space for you to show your working. It is important that you show your working, don't just write the answer down. You might earn marks for your working even if you get the answer incorrect.

Some maths questions might ask you to 'show that' something is true. These questions often require you to prove something mathematically. For example, you might have to calculate two values and then compare them.

In some maths questions you will be required to give the units. This may earn you an additional mark. Don't forget to check whether you need to do this.

Maths questions might include graphs and tables as well as calculations. Don't forget to take a ruler and calculator.

If drawing graphs, make sure you:

  1. put the independent variable on the x-axis and the dependent variable on the y-axis
  2. construct regular scales for the axes
  3. label the axes appropriately
  4. plot each point accurately
  5. draw a straight or curved line of best fit (you can use a special best fit line ruler to help with this)

If you are asked to calculate an answer and it has lots of significant figures, you should try to round it to the same number of significant figures you were given in the data in the question. Don't forget to check your rounding.

Edexcel questions courtesy of Pearson Education Ltd.

Sample question 1 - Foundation and Higher

Question

A car has a rechargeable battery to drive its motor.

The rechargeable battery provides a potential difference of 330 V and can store up to 64 MJ.

It takes eight hours for the battery to receive a full charge.

Assume that the charging process is 100% efficient.

a) Calculate the total charge that flows while the battery is being charged. [3 marks]

b) Calculate the average charging current. [3 marks]

a) Q = \frac{E}{V} [1]

Q = \frac{64,000,000}{330} [1]

= 193,940 C [1]

b) I = \frac{Q}{t} [1]

I = \frac{193,940}{8 \times 60 \times 60} [1]

= 6.7 A [1]

Don't forget to convert 64 MJ into J and the time of 8 hours into seconds.

Sample question 2 - Foundation and Higher

Question

When an LDR is in bright sunlight, its resistance is 185 Ω. The voltage across the LDR is then 7.2 V.

Show that the current in the LDR is about 0.039 A. [2 marks]

I = \frac{V}{R} [1]

= \frac{7.2}{185} [1]

= 0.039 A

In a 'show that' question, you can not use the number that you have been asked to show. Your calculation should have 0.039 A as the final answer.

Sample question 3 - Foundation and Higher

Question

The power of a kettle when it is heating water is 1.8 kW. The mains voltage is 230 V.

a) Calculate the current in the kettle. [3 marks]

b) The kettle is switched on for 2 minutes. Calculate the total amount of energy transferred by the kettle in this time. [2 marks]

a) I = \frac{P}{V} [1]

= \frac{1,800}{230} [1]

= 7.8 A [1]

b) E = Pt

= 1,800 \times 2 \times 60 [1]

= 216,000 J [1]

Don't forget to convert 1.8 kW into 1,800 W and remember that time should always be in seconds.