Before the test:
Preparation for numerical reasoning tests consists of two elements: Learning the required mathematical methods and practicing test questions. Solving practice tests is very important and can make a significant difference to how you perform in numerical reasoning tests. Before you start attempting questions though, you need to master certain basic mathematical techniques that you will need in solving the questions. The main areas to look at are:
 Four operations (addition, subtraction, multiplication, division)
 Percentages
 Ratios
 Currency conversions
You will need to apply these techniques to data given in a range of practical situations. You should familiarise yourself with:
 Methods of presenting data such as:
 Tables
 Bar charts
 Pie charts
 Trend lines
 Financial information such as:
 Income, costs, sale figures and profit
 Turnover, share prices
 Imports, exports and exchange rates
 Information about populations such as:
 GDP per capita
 Population growth
During the test:
The time spent in answering a particular question can be split into the following three parts, each of which you are trying to minimise.
 Understanding what the question asks: Understanding the question rapidly can only be improved by practicing. The questions are repetitive between tests, and even if you don’t get exactly the same questions, it is much faster to understand a question once you are familiar with many of them.
 Interpreting the data: Once what the question asks is clear, you need to find out where you will get the information from. For this part, you need to make sure you know how to read tables, charts etc. very well and then again, practice a lot.
 Doing the calculation that is required: This is where your knowledge and familiarity of mathematical methods come in. You should spend this time mainly on putting some numbers in your calculator (Using a calculator that you are familiar with is helpful, and I also suggest one that has bracket functions), and not thinking about how to do a certain calculation. This is only possible if you have already mastered the necessary mathematical techniques, and have a list of methods available in your mind.
Below is an example question with the steps I would go through to answer it. It is one of the more straightforward ones you can expect, but you should apply a similar thought process to all questions.
What is the ratio of the number of cars in Country A to the number of cars in Country B?

Country A 
Country B 
Population (m) 
45.3 
88.7 
GNP ($m) 
240,000 
350,000 
Cars (m) 
5.5 
11 
Telephones (m) 
6.1 
9.3 
 Keep a list of mathematical techniques that I know in my mind: ‘Finding percentage difference’, ‘ratios’, ‘currency conversions’ etc.
 Quickly identify which category the question falls under: Ratios
 Decide what information I need, in order to apply that technique: Two numbers, cars in Country A and Country B
 Look at the data to find that information: Country A=5.5, Country B=11
 Put the numbers in the calculator: 5.5:11 => 1:2
A final piece of advice I can give you is that you should not spend too much time on one question. All questions have equal weight and you can always get easier questions towards the end so make sure you have enough time to attempt all of them.