Civil Service Numerical Test practice

What the real test usually looks like

The CSNT is one of the Civil Service's own online tests. GOV.UK says it measures the ability to perform calculations and to evaluate and interpret numerical information to solve problems. You see graphs, tables or other numerical information, followed by a question with several possible answers, and you choose the right one (GOV.UK). Its guide to selecting tests lists the Numerical Test as untimed and available for every grade from AA/AO to G6, G7 and SCS 1 (GOV.UK). Your job advert or test invitation says whether your role uses it.

How the real test works (GOV.UK):

• It adapts to you. If you get a question right, the next may be harder; if you get it wrong, the next may be easier. So the test varies in length and is usually shorter than a fixed-length test.
• It is not timed. Most people take between 15 and 45 minutes, and GOV.UK says your score is not affected by how long you take. It recommends allowing at least an hour.
• You cannot skip or go back. Answer every question before you move on.
• Some questions are trial items. They are not scored; they help calibrate new questions for future tests.
• Have a calculator ready. GOV.UK suggests having rough paper, a pen and a calculator to hand.
• Example questions come at the start of each section, and the Civil Service publishes a free practice test that is not scored.

The Cabinet Office's transparency record adds that the test stops either when your score is measured precisely enough or when a fixed maximum number of questions is reached (GOV.UK). The maximum is not published.

What our mocks cover. Each full mock has 24 data interpretation questions in 40 minutes, all on tables of figures, with five answer options each. A calculator is allowed. As on the real test, you cannot go back to a question once you have moved on.

What our mocks leave out. The real test adapts to your answers and is untimed; ours is a fixed length with a time limit, so every mock is comparable and you build a steady pace. Our questions use tables, not graphs or charts.

Question types with worked examples

One worked example of each common calculation, with the trap most people fall into.

1. Percentage change. A team handled 250 cases last year and 290 this year. The change is 40, and 40 / 250 = 16%. Trap: dividing by the new figure (40 / 290 = 13.8%). Always divide by the starting value.

2. Share of a total. Three offices spend £30,000, £45,000 and £75,000. What share is the largest? The total is £150,000, and 75 / 150 = 50%. Trap: forgetting to add up the total first, or using a total from the wrong year.

3. Ratio. 180 full-time and 60 part-time staff give 180:60, which simplifies to 3:1. Trap: reversing the order. Write the ratio in the order the question asks for.

4. Weighted average. Office A has 100 staff averaging 4 training days; office B has 300 staff averaging 8. The combined average is (400 + 2,400) / 400 = 7, not (4 + 8) / 2 = 6. Trap: averaging the averages when the groups are different sizes.

5. Projection. A cost of £2,000 rising by 10% a year becomes £2,200 and then £2,420. Trap: adding the first year's increase again (£2,400). Each new rise is on the latest figure.

6. Reading the table. Before calculating, check the units (thousands, percent, per person) and the year. Trap: answering correctly for the wrong row or column.

How to prepare

1. Read your job advert first. It says which online tests the role uses, so you know what to practice.
2. Take the Civil Service's own practice test. It shows the real screens, and GOV.UK also offers a short video on the Numerical Test (GOV.UK).
3. Have your tools ready. Rough paper, a pen and a calculator you know how to use. GOV.UK suggests all three.
4. Master five calculations. Percentage change, percentage of a total, ratio, average and a simple projection cover most table questions.
5. Check the starting value. For every percentage change, ask "change from what?" before you divide.
6. Estimate before you calculate. A quick rough answer helps you spot a wrong option and a calculator slip.
7. Commit to each answer. You cannot go back on the real test, so check your working once, then move on. Our full mocks work the same way.
8. Take your time on the day. The real test is untimed and GOV.UK says your score is not affected by how long you take (GOV.UK). Accuracy matters more than speed. Our timed mocks build focus, not a rush.

How scoring usually works

GOV.UK explains the scoring in general terms (GOV.UK):

• The number and difficulty of the questions you answer are used to produce your score.
• Your score is compared with a representative group of applicants who took the test, and shown as a percentile.
• Trial items are not scored, and how long you take does not affect your score.
• If you do not reach the minimum standard for a job level, you can take the test again in a future application. A score that does not pass is not banked.

The Cabinet Office's transparency record adds that a raw score is converted to a percentile by comparing it with a benchmark group of test takers (GOV.UK). GOV.UK does not publish a fixed pass mark.

Our practice score is the number of our own questions you answered correctly, out of 24 in a full mock, with every calculation worked through. It is a practice score: it is not a Civil Service score or percentile, and it does not predict whether you will pass.

Common mistakes on data interpretation questions

• Dividing by the wrong figure. Percentage change always uses the starting value.
• Averaging averages. When groups are different sizes, add the totals first.
• Missing the units. A table in £ thousands means 2,205 is £2,205,000.
• Reading the wrong year. Many tables show two or three years side by side.
• Adding percentages across years. Two 10% rises make 21%, not 20%.
• Rounding too early. Keep the full figure on your calculator and round only the final answer.

A one-week study plan

• Day 1: Take the free sample above. Note which calculations cost you time or marks.
• Day 2: Read GOV.UK's guidance and take the Civil Service practice test.
• Day 3: Percentage change and share of a total. Ten questions of each, starting value checked every time.
• Day 4: A full timed mock with no going back. Review every explanation.
• Day 5: Ratios, weighted averages and projections, the three most common traps.
• Day 6: A second mock. Compare your score by calculation type with the first.
• Day 7: A short review in the morning, then rest. Set out paper, a pen and your calculator for the real test.