Science calculations
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.
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:
- put the independent variable on the x-axis and the dependant variable on the y-axis
- construct regular scales for the axes
- label the axes appropriately
- plot each point accurately
- decide whether the origin should be used as a data point
- draw a straight or curved line of best fit.
If you are asked to calculate an answer and it has lots of decimal places, don't forget to use the same number of significant figures as the data in the question. For example, if two significant figures are used in the question, then usually your answer would also be to two significant figures. Don't forget to check your rounding.
These questions have been written by Bitesize consultants as suggestions to the types of questions that may appear in an exam paper.
Sample question 1 - Foundation
Question
The number of people living with HIV each year is recorded by the UN. The data for recent years is shown in the table below.
| Year | 2000 | 2005 | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 |
| Infected people (millions) | 28.9 | 31.8 | 33.3 | 33.9 | 34.5 | 35.2 | 35.9 | 36.7 |
| Year |
|---|
| 2000 |
| 2005 |
| 2010 |
| 2011 |
| 2012 |
| 2013 |
| 2014 |
| 2015 |
| Infected people (millions) |
|---|
| 28.9 |
| 31.8 |
| 33.3 |
| 33.9 |
| 34.5 |
| 35.2 |
| 35.9 |
| 36.7 |
Plot these points on the graph paper below. Draw a line of best fit. [4 marks]
Your graph should be similar to this one:
Answer (four from):
- years on the x-axis
- number of infected people (millions) on the y-axis
- scales at regular intervals
- axes labelled
- all points plotted accurately
- curved line of best fit drawn
Sample question 2 - Foundation
Question
A single bacterium divides every 20 minutes by binary fission. Estimate how many bacteria would be present after 6 hours? [2 marks]
- the bacterium will divide three times each hour and so 3 脳 6 = 18 times in total
- 1 脳 218 = 262,144
Sample question 3 - Higher
Question
Write 67108864 in standard form to two decimal places. [1 mark]
6.71 脳 107
Sample question 4 - Higher
Question
The diameter of a bacterial colony on an agar plate is 2 mm. Calculate the area of the colony to two decimal places. [2 marks]
1 mark for calculation and 1 mark for units:
- area = 蟺r2
- area = 3.14 脳 112
- Area = 379.94 mm2