Mathematics is a standard part of almost every pilot assessment. It is not about complicated formulas but about calculating quickly and accurately, a skill you need every day in the cockpit. Cognitive tests for aspiring pilots include maths, such as mental arithmetic, units and conversions. The arithmetic test in pilot assessments covers mental arithmetic, fractions and percentages, ratios, units and conversions, and the formula D=S×T (distance = speed × time). All of this is done under time pressure. Most calculation questions in pilot assessments must be solved without a calculator. The maths section of the COMPASS test in one flight school's selection covers mental arithmetic, and in 2022 this consisted of 24 questions in 20 minutes. The sums are not extreme, such as 3454:43 or 3454x434, but time is the limiting factor. An applicant in 2025 reports that the maths and physics test at Skywings (Brussels Airlines MPL) is longer and more tiring than the sample exam, partly because it comes after COMPASS. According to the applicant, the content is no harder than expected and follows the topics on the website.12345

Prepare as if you have to work without a calculator: if you can calculate quickly in your head, you have an advantage. Start practising months before your selection date, not weeks, because aptitude skills such as mental arithmetic under time pressure improve with training, but not over a weekend. Turning up unprepared, rusty maths and nerves are common causes of rejection. Practising 10-15 minutes a day already makes a big difference. A successful candidate in the KLM Flight Academy selection in 2022 prepared for about seven months. This candidate brushed up on maths, physics and mental arithmetic, practised computer tests with software and read experiences online. For mental arithmetic, practise multiplications up to 20×20 daily, percentages (10% = divide by 10, 25% = divide by 4) and adding and subtracting fractions. Quick tricks are 15% = 10% + 5% and 33% ≈ ⅓. Useful conversions for the arithmetic test are nautical miles to kilometres × 1.852; feet to metres × 0.3048; knots to km/h × 1.852; pounds to kilograms × 0.4536; US gallons to litres × 3.785. Use D=S×T for fuel planning, arrival time calculations and distance estimates. For the maths section of COMPASS, practise basic arithmetic rules, written arithmetic, long division and fractions, and focus above all on your speed. Practise numerical skills in context, such as tables, ratios and word problems. Brush up your basic mathematics, especially if your final exams were a while ago. Practise briefly and regularly, with a clock, and pay attention to accuracy: calculating fast is of little use if it leads to careless mistakes.13567

Candidates find the mental arithmetic test harder than expected. One candidate noted, "I failed on this myself". In 2007, the practice tests online were easier than the real test. Time pressure is a key factor; at a private pilot licence (PPL) school on Gran Canaria in 2024, time pressure was the hardest part of the maths and physics and mental arithmetic entrance test, where one applicant had 1 minute 15 seconds per question without a calculator. A candidate who did the selection of the KLS (now KLM Flight Academy) in 2018 says the mental arithmetic questions are manageable with practice and that you should not let yourself be scared off. According to four candidates in 2025, the maths and simulator questions in phase 2 of one flight school's selection are manageable if you have kept your numerical skills up to date.12368

You only reach the Basic Capacities Assessment (BCO) once you have passed the pre-selection, and you are invited only if all parts are good enough. The BCO is an assessment of your intellectual abilities, and the arithmetic section falls under numerical abilities. If you meet the minimum requirements, you continue to the Sensorimotor Assessment (SMO) after the lunch break. If you fail, the selection stops at that point. Candidates report that applicants often fail phase 1 (BCO) of the KLM Flight Academy selection, because a single component below the norm is enough to stop you progressing. Numerical ability is one of the components taken under heavy time pressure. According to candidates, the arithmetic in phase 1 of the KLM Flight Academy selection is multiple-choice mental arithmetic under time pressure, with 20 to 30 seconds per question in 2023. An applicant in 2018 reports that the arithmetic test in the KLS selection consists of mental arithmetic questions to be answered within 10 seconds, such as 6x6x6, 12x24, 0.1 x 0.03, 16050/50, 888/16, 18x18 and 767+870, plus simple fractions. In 2023 and 2025, candidates were allowed to use pen and paper for arithmetic and multitasking in the KLM Flight Academy selection. According to an applicant in 2011, you were given scrap paper for the mental arithmetic test in the first psychological assessment (PO1) of the KLS selection (KLM Flight Academy). An applicant in 2008 who knew little about long division still got through PO1 of the KLS selection without problems. According to this applicant, quick estimation methods often let you rule out 3 of the 4 answers, and a great many people get through the arithmetic component. Another candidate passed PO1 of the KLS selection in 2007 with a 3 for numerical skills and was eventually accepted. One candidate was eliminated in January 2025 in the KLS selection of KLM Flight Academy on numerical skills and spatial awareness. A candidate who was eliminated on numerical skills in the KLS selection of KLM Flight Academy in 2025 then started preparing for a COMPASS test. A candidate who failed on numerical skills in the KLM Flight Academy selection in 2024 said the component was harder than expected, but can be trained well.12468