An interactive calculator is included in the interactive benchmark and practice tests and can be activated by clicking on the 'calculator' button near the top left-hand corner of the screen. Once opened, the calculator can be moved around the screen to the most appropriate position. To do this, click on the dark green bar at the top of the item and move the calculator around, holding the mouse button down until it is in the required position.

The on-screen calculator works through the mouse and through the number pad on the keyboard. First ensure that the number lock key - labelled 'Num Lock' is activated before the number keys on the right of the keyboard may be used.

Things to consider when using the on-screen calculator

• To cancel an operation, press . This will save time if an error has been made when entering a long list of numbers. 
• Always press the 'clear' button  on the calculator before beginning a new calculation. 
• Always look at the display of the calculator after entering a number to check that the number shown is correct. 
• If entering the division sign in an answer via the keyboard, instead of using the mouse, you need to press the  key, as there is no ÷ sign on the keyboard. 
• Check the calculations and check the final answer makes sense in the question context. For example, 2.43 pupils would not be a reasonable answer.

Rounding up and down

Please ensure that any instructions to round an answer up or down are followed or the answer will be marked as incorrect.

When working out how many lessons are required for a particular activity, an answer on the calculator of 15.33 would need to be rounded up to 16 lessons.

Questions may specify that the answer should be rounded to the nearest whole number or be rounded to two decimal places. So, 9.237 rounded to the nearest whole number would be 9; 7.5 to the nearest whole number is 8; 33.857 rounded to two decimal places would be 33.86.

When carrying out calculations relating to money, the answer shown on the calculator display will need to be rounded to the nearest penny (unless otherwise indicated). Hence, if calculating in pounds, round to two decimal places to show the number of pence. If 10.173 is the answer in pounds on the calculator display, rounding to the nearest penny gives £10.17.

Answering multi-stage questions

The calculator provided is not a scientific calculator and therefore care needs to be taken for 'mixed operations', ie. calculations using several function keys. It is important that the function keys are pressed in the appropriate order for the calculation. It may also be useful to note down answers to particular stages of the calculation.

It is important to remember to carry out the calculation required by the question in the following order: any calculation within brackets followed by division/multiplication followed by addition and/or subtraction.

Fractions

To enter fractions, using the division sign, eg.  of 350, enter 5 ÷ 8 to reach 0.625 then multiply by 350 to reach 218.75.

If the keyboard is used to enter numbers rather than using the mouse, enter .

Percentages

When carrying out a calculation using percentages, think of 'per cent' as meaning 'out of a hundred' or 'divided by a hundred'. Therefore,
1% is , which is equivalent to 0.01

10% is 0.1

100% is 1

0.85 is 85%

0.06 is 6%

To carry out the calculation 73% of 320, on a calculator, first think of 73% as a decimal number, 0.73, then enter 0.73 x 320 = 233.6.

Refer to the ‘Practice materials’ section on Fractions, decimals and percentages for further guidance.