NATS Numerical Reasoning Test: What to Expect and How to Pass

Numerical ability is one of the skills NATS lists for its Stage 1 online tests. It assesses your ability to interpret data, perform calculations under time pressure, and draw accurate conclusions from numerical information — all skills central to operational ATC work.

What the Test Measures

Air traffic controllers work with numbers constantly: altitudes, headings, speeds, separation distances, and time calculations. Numerical tests in ATC selection usually go beyond mental arithmetic: they check you can pull the relevant information out of data and apply it correctly while working quickly.

Format and Question Types

NATS doesn't publish its test content, but numerical tests in ATC selection commonly include:

Data interpretation questions — A table or chart is presented alongside a question. You must read the data correctly, identify the relevant figures, and calculate the answer. Common formats include flight data tables (callsigns, altitudes, speeds), bar charts, and line graphs.

Ratio and proportion questions — You may be asked to calculate what percentage of aircraft meet a certain criterion, or compare rates across two data sets.

Multi-step calculations — Some questions require two or three operations in sequence: for example, converting between units and then calculating a ratio.

Number sequences — Less common, but some versions include sequences where you identify the rule and predict the next number.

Time Pressure

The test is strictly timed. Most candidates report that speed is as limiting as difficulty — the questions are not necessarily hard, but there are many of them and the time per question is tight. Building fluency with mental arithmetic (particularly percentages, fractions, and multiplication) significantly reduces the time per question.

The Most Common Mistakes

Reading the wrong column or row. Data tables often contain many figures. Candidates under pressure frequently pick up the wrong value. Always confirm which row and column the question refers to before calculating.

Rounding too early. Intermediate rounding in multi-step questions introduces errors. Keep full precision until the final answer.

Not checking units. If the table shows speed in knots and the question asks about kilometres, you will get it wrong without converting first. Read the units carefully.

Spending too long on one question. If a question is taking more than 90 seconds, mark a best guess and move on. Losing three easier questions to rescue one hard one is poor strategy.

Effective Preparation

Practice data table questions specifically. Generic maths practice helps, but time spent reading data from tables under time pressure is especially useful.

Build mental arithmetic speed. Practice percentage calculations, ratio comparisons and multiplication in your head. Reducing reliance on written workings saves crucial seconds.

Simulate timed conditions. Doing questions with no time limit does not train the skill the test is actually measuring. Always practice with a stopwatch.

Review every wrong answer. Understanding why you made an error is more valuable than additional practice questions. Most candidates make the same two or three types of mistake repeatedly.

What Score Do You Need?

NATS doesn't publish pass marks or say how the tests are scored. Aim for consistent, accurate answers at speed rather than occasional perfect runs — and remember you'll be retested under observation at Stage 3.