Module 1 / 1.1 Arithmetic
EASA Part 66 Module 1.1 — Arithmetic
Arithmetic (sub-module 1.1) is the numerical bedrock of EASA Part 66 Module 1. It tests whether you can work quickly and accurately with numbers — fractions, decimals, percentages, ratios and powers — the everyday calculations that appear again and again across the B1/B2 modules. None of it is advanced, but the exam rewards speed and precision, so the goal is to make these operations automatic.
What's covered
- Arithmetical terms and signs; order of operations
- Multiplication and division of whole numbers
- Fractions and decimals, and converting between them
- Factors and multiples (highest common factor and lowest common multiple)
- Weights, measures and conversion factors
- Ratio and proportion
- Averages (the mean)
- Percentages, including percentage change
- Powers, indices, squares, cubes and roots
- Areas and volumes of common shapes
Worked examples
Increase 80 by 15%.
15% of 80 = 0.15 × 80 = 12. So 80 + 12 = 92.
Share 45 litres of fluid in the ratio 4:5.
Parts = 4 + 5 = 9. 45 ÷ 9 = 5 litres per part. Shares: 4 × 5 = 20 litres and 5 × 5 = 25 litres.
What is 2⁴ × 2³?
Add the indices for powers of the same base: 4 + 3 = 7, giving 2⁷ = 128.
Exam tips
- Learn the order of operations (BIDMAS) cold — a surprising number of marks are lost to it.
- Practise converting fluently between fractions, decimals and percentages; the exam mixes all three.
- Keep your unit conversions straight (mm ↔ m, cm^3 ↔ m^3); conversion errors are a common trap.
Practise arithmetic questions
The question bank has hundreds of Module 1.1 arithmetic questions, each with a worked explanation and graded by difficulty.
Independent practice material, not affiliated with EASA. Check the current official EASA Part 66 syllabus for the definitive scope.