How to Use a Calculator | Tips, Tricks & Techniques for Numerical Tests

Improve Your performance on Numerical Reasoning Tests by  Becoming a Calculator God

Why You Should Master Your Calculator

The main difficulty in numerical reasoning tests is not the math, rather the time constraints. Knowing how to perfectly solve a question will not help if your calculations are slow.

Understanding your calculator and using its functions efficiently will be a key factor in your test performance.

We get very specific about how to use your calculator in the most proficient way further down this page.

If you feel you're ready to jump into the practical (and complicated) stuff, go ahead and click here - otherwise keep reading and we'll ease you into it.

Is a Calculator Allowed?

It is crucial that you know whether you're allowed a calculator ahead of time and prepare accordingly. This information should be provided on your test announcement. If it is not, do not hesitate to contact the HR department and ask.

As a rule of thumb, there are 3 types of tests with different approaches towards calculators:

  1. Calculation Tests: Calculation tests focus on your ability to perform basic calculations, mostly in the four operations. As such, no calculator is usually allowed in these tests. (Learn more)
  2. Cognitive Ability Tests: Here your ability to solve a large number of simple mathematical questions in a short period of time is put to the test. These tests also do not permit calculators. (Learn more)
  3. Numerical Reasoning Tests: Lastly, these traditional tests assess your ability to solve problems and draw conclusion from numerical data. As calculation is not considered the main measured ability of this test, calculators are sometimes allowed (Learn more).


Types of Calculators

There are 2 types of calculators: 1) simple and 2) scientific.

Different calculators

A simple calculator enables very basic functions such as:

  • Addition (+), subtraction (-), multiplication (x) and division (÷)
  • Percentage calculation
  • 1 memory item (see below)

Meanwhile, a scientific calculator has a much broader range of options, including square roots and exponentials, logarithms, brackets etc.


Which Calculator is Allowed?

Most numerical reasoning tests only allow the use of simple calculators – but double check with your HR department. Sometimes, the definition of which calculators are allowed is based on their range of functions, e.g. four operations, percentage and square root.

Note: If a scientific calculator is allowed, the test provider will usually publish a list of allowed models.


Calculating Techniques

1) Using the memory in simple calculators

Although a pocket calculator allows for only the most basic of functions, it can save at least one number in its memory which can be of use for the next calculation. This can be done in several easy steps:

  1. View the number you wish to save
  2. Click on M+. The number is now saved to the calculator’s memory
  3. Pressing the MRC button (memory recall) will place the saved number onto the screen, allowing immediate usage for your next calculation

Let’s assume that we saved the number 12 to memory. We then begin a new calculation by pressing the number 36, and then pressing the division sign.

Finally we press the MRC button, which will place the number 12 after the divisor, giving us the equivalent calculation of 36/12. Pressing the equal sign will give us the correct result of 3.

Alternatively, we could have stored the number 36, and recalled it from memory at the beginning of the calculation.

Remember, a double click on the MRC button will clear the memory of any saved numbers.

In addition, we can add or subtract from the value stored in the memory directly by clicking on the M+ or M- buttons.

For example: Assuming we store 10 into the memory, we should:

a) Select the number 15

b) Press M- the calculator will subtract 15 from the value saved in the memory, giving us -5

c) Store that number in its place in the memory.

Similarly, pressing the M+ button when a number is displayed will add that number to the one stored in the memory.

2) Create a calculation plan

When a question requires more than one calculation step, it is extremely important to think ahead and organise the operations.

This way, there would be minimum use of paper and maximum usage of the calculator, since you can perform all the calculations in a row.

Test writers are aware of this strategy and create questions that provide this shortcut. Thus, it’s important to use it, otherwise you may waste precious time.

Example 1 - Government Construction Contracts (%)

Of 400 contracts were offered for £22,200 each. In 2009, contract value increased by 7%, and there was a 25% decrease in the number of contracts.

How much more money than Buildingo did Roads do in 2009?






View Explanation

The correct answer is E (213,786)


1) Create a template. Since the question asks, ‘How much more …’, it would look like:

Answer = IncomeRoads - IncomeBuildingo


2) Break each part of the template into smaller parts:


Income = NC ⋅ PC

NC = TNC ⋅ Share(%)



TNC = Total Number of Contracts

NC = Number of company's Contracts

PC = Price per Contract

Share = Company's share of the contracts (from the graph)


So the final template will look as follows:

Answer = (TNC ⋅ Share ⋅ PC)Roads - (TNC ⋅ Share ⋅ PC)Buildingo


3) Identify common multipliers to minimize the template

We know that the price per contract PC is similar in all cases:

PC = £22,200 x 1.07 = £23,754.

We know that the total number of contracts TNC is 400 x 0.75 = 300.

The only difference between Roads and Buildingo is their share:

Buildingo has a share of 9%, Roads has a share of 12%.


4) Rearrange, plug in numbers and calculate once.

Now, after rearranging the numbers, our template will look like:

Answer = (300 ⋅ 23,754) x (0.12 - 0.09) = 213,786

3) Look for repetitive operations

Always ask yourself - is there a specific operation that will be used more than once? If so, treat it like a common multiple, and leave it to the last step.

Consider this example:


Example 2

If a driver covered 500 miles with Navut's vehicle and 325 miles with Muto's, how many gallons did he end up using in total?





View Explanation

Solution: This question involves converting units, so it's a classic example for applying the technique.


1) Find the main and secondary calculations:

The main calculation is the reasoning part of the question. What mathematical drill do you need to solve?
First, find the amount of fuel used in two trips combined. You can do this by dividing each trip by the fuel consumption.
The secondary calculation is the calculation part of the question. What small calculations do you need to preform to get to the final answer? These may include:
Unit/currency conversions
Decimals/percentage conversions
Think of some more
Next, convert miles to km and litres to gallons.


2) Perform the main calculation:

Navut's fuel usage: (500 miles)/(16.4 km/litre) = 30.48. 
We save this to our memory by pressing M+.
Moving on to Muto's: (325 miles)/(14.7 km/litre) = 22.10.
Now we can add this number to the stored result in our memory by pressing + and then MRC to get: 30.48 + 22.1 = 52.596 = 52.6


3) Perform the secondary calculation:

Divide the above sum by 0.62 to get km instead of miles
Then divide by 4.546 to get gallons instead of litres: 52.6/0.62/4.546 = 18.66 gallons.
If have you problems with the unit conversion procedure, check out our numerical practice tests in which an entire section is dedicated to this topic.


4) Always leave the last calculation on screen:

Don't restart the calculator. There are great chances you will be using the last calculation in the next step. 


5) Remember the order of operations:

A simple calculator performs only one calculation at a time.  That means that if you type:

10 + 3 x 2 – 7


The calculator will calculate:

10 + 3 = 13

13 x 2 = 26

26 - 7 = 19


Whereas the correct calculation is:

3 x 2 = 6

10 + 6 = 16

16 – 7 = 9


Note: That simple an error can ruin the entire well-thought calculation, so pay attention.

Final Tips

1. Practise quickly ­– efficient calculation work is an important part of success in the test.

2. Use your calculator for everything. If you're allowed a calculator, use it for even the most basic drills. It's faster, more accurate and no one will know that you've previously typed something into your calculator.

3. Bring a spare calculator with you (if you can). You don't want to be left high and dry if your calculator malfunctions during the test.


Good luck!