Cheat sheet

EASA Part-66 Module 1 Cheat Sheet

Arithmetic

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Algebra - Expressions & Equations

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Algebra - Indices, Logs & Number Systems

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Geometry - Constructions & Graphs

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Geometric ConstructionsGraphs of FunctionsStraight-Line GraphsGradient & Intercept

Trigonometry & Coordinates

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Trig Ratios & Standard AnglesPythagoras & CoordinatesRight-Angle TrianglesPolar Coordinates

Quick Facts

Exam
Part-66 Module 1
Credential
Aircraft Maintenance Licence
Questions
32 (Cat B1/B2)
Time
40 min (Cat B1/B2)
Pass
75% per module
Format
Multiple choice, 3-option
Level
Foundation module
Blueprint
Reg (EU) 2023/989

HCF vs LCM

HCF

  • Largest shared factor
  • Used to simplify fractions

LCM

  • Smallest shared multiple
  • Used to add fractions

Divides into vs divisible by

Which Operation to Apply

  1. Fraction plus fractionFind common denominator first(Then add numerators)
  2. Percentage change wantedMultiply base by percent(Add or subtract result)
  3. Ratio shares a totalDivide total by parts(Multiply per share)
  4. Need area of circleπ times radius squared
  5. Need volume of cylinderπ r² times height
  6. Need average of valuesSum values, divide by count

Fractions & Decimals

1/2
0.5 or 50%
1/4
0.25 or 25%
3/4
0.75 or 75%
1/8
0.125 or 12.5%
5/8
0.625 or 62.5%
Add/subtract fractions
Use common denominator first
Multiply fractions
Top times top, bottom times bottom
Divide fractions
Multiply by the reciprocal

Area vs Volume

Area

  • Two dimensions only
  • Measured in square units

Volume

  • Three dimensions total
  • Measured in cubic units

Flat surface vs solid space

Ratio, Percentage & Averages

Ratio a:b
Split total into a+b parts
Percentage of X
(part ÷ whole) × 100
Increase by %
Add the percentage amount
Decrease by %
Subtract the percentage amount
Mean (average)
Sum of values ÷ count
HCF
Highest common factor of numbers
LCM
Lowest common multiple of numbers

Areas, Volumes & Roots

Rectangle area
Length times width
Triangle area
Half of base times height
Circle area
π times radius squared
Circle circumference
2 times π times radius
Cylinder volume
π times radius² times height
Box volume
Length times width times height
Square/cube root
Inverse of squaring or cubing

Units & Conversions

1 metre
1000 mm or 100 cm
1 kilogram
1000 grams
1 litre
1000 millilitres
1 tonne
1000 kilograms
Scale 1:50
Drawing length times 50

Order of Operations

Brackets, Indices, Divide, Multiply, Add, Subtract

Brackets firstThen indices/powersThen divide and multiplyThen add and subtract

Solving Equations Selector

  1. One unknown, one equationIsolate the unknown
  2. Two unknowns, two equationsElimination or substitution
  3. Brackets in expressionExpand brackets first
  4. Unlike terms presentCollect like terms only
  5. Fraction with unknownMultiply to clear fraction
  6. Need to verify answerSubstitute back into equation

Algebraic Expressions

Like terms
Combine matching variables only
Expand brackets
Multiply each term inside
Substitute value
Replace the letter with number
Algebraic fraction
Cancel common factors first
x² ÷ x
Subtract powers, result is x

Linear & Simultaneous Equations

Linear equation
Solve for one unknown
Isolate x
Same operation on both sides
Simultaneous equations
Two unknowns, two equations needed
Elimination method
Add or subtract the equations
Substitution method
Substitute one equation into other
Check your solution
Plug values back into equations

Binary Place Values

Powers of two: 1, 2, 4, 8, 16, 32

Rightmost digit is onesEach place doubles leftwardHex A-F equal 10-15

Binary vs Hexadecimal

Binary

  • Base 2
  • Digits 0 and 1 only

Hexadecimal

  • Base 16
  • Digits 0-9 then A-F

Fewer digits vs more digits

Indices, Logs & Number Base Selector

  1. Multiplying same base powersAdd the indices
  2. Dividing same base powersSubtract the indices
  3. Power of zero seenResult is always 1
  4. Negative index shownTake the reciprocal
  5. Fractional index (1/2)Take the square root
  6. Base other than 10Convert to decimal first

Indices & Powers Laws

x^a × x^b
Add the indices (a+b)
x^a ÷ x^b
Subtract the indices (a−b)
x^0
Always equals 1
x^-a
Reciprocal: 1 divided by x^a
x^(1/2)
Same as square root of x
(x^a)^b
Multiply the indices (a×b)

Number Systems

Binary base
2, digits 0 and 1
Octal base
8, digits 0 through 7
Hexadecimal base
16, digits 0 through F
Binary place values
1, 2, 4, 8, 16, 32
Binary 1011
Equals decimal 11

Logarithms & Quadratics

log₁₀ 1000
Equals 3 (10³ = 1000)
Logarithm meaning
Power needed to reach number
log(ab)
Add logs when multiplying
x² = 9
x equals plus or minus 3

Gradient vs Y-Intercept

Gradient

  • Coefficient of x
  • Steepness of the line

Y-intercept

  • Constant term c
  • Where line meets y-axis

Slope vs starting point

Geometric Constructions

Right angle
Exactly 90 degrees
Bisect
Divide into two equal parts
Perpendicular lines
Meet at 90 degrees
Parallel lines
Never meet, same direction
Scale drawing
Proportional to the real size

Graphs of Functions

y = mx + c
m is gradient, c is intercept
Gradient
Rise over run (slope)
y-intercept
Where the line crosses y-axis
x-intercept
Where y equals zero
Distance-time graph
Gradient equals speed
Speed-time graph
Gradient equals acceleration

SOH-CAH-TOA

Sin=Opp/Hyp, Cos=Adj/Hyp, Tan=Opp/Adj

Sin: opposite over hypotenuseCos: adjacent over hypotenuseTan: opposite over adjacent

Sine vs Cosine

Sine

  • Opposite ÷ hypotenuse
  • Rises 0 to 1

Cosine

  • Adjacent ÷ hypotenuse
  • Falls 1 to 0

Opposite side vs adjacent side

Trig & Coordinates Selector

  1. Know two triangle sidesApply Pythagoras theorem
  2. Need opposite over hypotenuseUse sine ratio
  3. Need adjacent over hypotenuseUse cosine ratio
  4. Need opposite over adjacentUse tangent ratio
  5. Point given as (x,y)That is rectangular form
  6. Point given as radius/angleThat is polar form

Trig Ratios & Standard Angles

SOH-CAH-TOA
SOH-CAH-TOA (opp/adj/hyp)
sin 30°
Equals 0.5
sin 45° = cos 45°
Equals 0.707
sin 60° = cos 30°
Equals 0.866
tan 45°
Equals 1.0 exactly
cos 0°
Equals 1.0, maximum value
sin 0°
Equals 0

Standard Trig Values

Memorise sin 30, 45, 60 degrees

sin 30° = 0.5sin 45° = 0.707sin 60° = 0.866tan 45° = 1.0

Rectangular vs Polar Coordinates

Rectangular

  • Uses (x, y) values
  • Perpendicular axes

Polar

  • Uses radius and angle
  • Distance plus direction

Position vs distance and angle

Pythagoras & Coordinates

Pythagoras
a² + b² = c²
3-4-5 triangle
Common right-triangle number set
5-12-13 triangle
Another common right triple
Rectangular coordinates
Given as (x, y)
Polar coordinates
Given as radius and angle
Polar radius
Square root of x²+y²

Common Traps

Area ≠ Volume

Area is length times width Volume adds a third dimension

HCF ≠ LCM

HCF divides both numbers LCM is divisible by both

Sine ≠ Cosine

Sine uses opposite side Cosine uses adjacent side

Gradient ≠ Y-Intercept

Gradient is coefficient of x Intercept is the constant term

Add Indices ≠ Multiply Indices

Multiplying powers adds indices Raising a power multiplies indices

Rectangular ≠ Polar Coordinates

Rectangular uses x and y Polar uses radius and angle

Last Minute

  1. 1.32 questions, 40 minutes (B1/B2)
  2. 2.16 questions, 20 minutes (Category A)
  3. 3.75% pass mark per module
  4. 4.Real exam uses 3 options
  5. 5.Common denominator before adding fractions
  6. 6.Multiply indices when raising powers
  7. 7.Add indices when multiplying powers
  8. 8.Negative index means take reciprocal
  9. 9.SOH-CAH-TOA for right triangles
  10. 10.Gradient is coefficient of x
  11. 11.Pythagoras: a² + b² = c²
  12. 12.Hex digits A-F equal 10-15
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