How the Technical Selection Test works
The TST is a maths test for soldier applicants to technical trades. The Army has named trades in the Royal Engineers, the Royal Electrical and Mechanical Engineers and the Royal Corps of Signals, and Ammunition Technician in the Royal Logistic Corps. Your recruiter tells you whether your role needs it.
The Army describes the questions as similar to those in a GCSE textbook. In 2025 an Army recruiting coordinator said that if you need a TST, it is not done at the Assessment Centre.
Preparation sites report 55 multiple-choice questions in 45 minutes, marked out of 55 with one mark per correct answer and nothing taken off for wrong ones. A candidate who sat it describes a paper test with a calculator provided.
How to approach the paper
At about 49 seconds a question, manage the paper rather than working straight through:
- First pass: answer everything you can do in under a minute.
- Mark the longer questions and come back to them.
- Estimate before you calculate, so an option ten times too big stands out.
- Never leave a blank. With no negative marking, a guess among five options costs nothing.
- In word problems, write the units next to each number before you start.
Worked example
A van uses 9 litres of diesel for every 100 km. How much does it use on a 340 km round trip? A. 27.0 l, B. 30.6 l, C. 34.0 l, D. 36.0 l, E. 306 l.
340 km is 3.4 lots of 100 km, so the van uses 3.4 × 9 = 30.6 litres: B. Option E slips the decimal point, and C simply divides the distance by ten.
An algebra question: solve 3x − 7 = 2x + 5. Take 2x from both sides to get x − 7 = 5, then add 7: x = 12.
Tips for the real TST
- Revise the reported topics: arithmetic, decimals, fractions, percentages, ratio, algebra, geometry, standard form, simultaneous equations and reading graphs.
- Use free GCSE revision such as BBC Bitesize, which Army staff point applicants to.
- Ask your recruiter where and when you will sit it, and whether a calculator is provided.
- Learn the formulas you will not be given time to derive: area of a circle, Pythagoras, and speed equals distance over time.
- Ask your recruiter for your trade’s minimum score, since it varies by role.
Practise the TST on CogniPrep
Our TST practice is a 55-question paper in 45 minutes, five options per question, with the clock shown throughout. You can move back and forward, flag questions and jump around with a question map, as you would on paper, and an on-screen calculator is there if you want it. You get a mark out of 55 with no negative marking, plus the GCSE topic that cost you most. The count, time and marking follow a preparation site’s account, because the Army publishes none.