Why does 0.99999... = 1?
3.1415... : KEY 174-178, PSAUS 15, 150-152,
LUCKY 143-147, MM2 89-94,
EQEA 24, ASAS 52-57
4 Colour Map Theorem: Four Colour Map Theorem
9: KEY 151-163
11: Can I divide the world into football teams? EQEA 14, When will a number divide by 11?
12: 12 Coin Balance Problem
13: fear of KEY 78-89
37: KEY 37
1089: MM1 78-80, 1089 times table EQEA 15-16, 1089
2018: 2018 The Nine-Bead Necklace Number
4 4's: Sunny's Four 4's Challenge
Abacus: MM1 33-34
Acceleration: PSAUS 46-54
Accuracy: measurement DMEAS 27
Activities: see our Teacher Resources page
Addition: SOS 22-34, AWAR 19-31
Algebra: PHX (entire book), card trick MM1 116-124
Alternate Segment: The Alternate Segment Theorem & Proof
Amicable numbers: KEY 148-150
Angles: ASAS 16-23, DMEAS 115-126, MM1 73-78, opposite, corresponding SAVSH 16-17, very small FANG 138-158
Angstrom: DMEAS 21
Annulus: formula PSAUS 163-165, The area of an ANULUS
Archimedes: BBB 29-40, principle DMEAS 135-144, MM1 10, DMEAS 150-157, sphere formula PSAUS 167-170
Arcsecond: FANG 138-139
AREA: formulas PSAUS 10, 116-142, measuring ASAS 75-90, DMEAS 92-110, Area calculator
Articles: Stories from "The Week" that amused us, The Cicadas 17-year Life Cycle, The Al-Gebra Movement, Cool Greek Maths Geeks
Astonomical Unit (au): FANG 155
Averages: MANDV 124-156
Babylonians: KEY 128
Base 8: KEY 126-127
Bear Hunter Puzzle: SAVSH 63-65, The Bear Hunter Puzzle
Bearings and navigation: FANG 181-196
Bell ringing: LUCKY 99-103
Big numbers: MM1 130-135, EQEA 119-128
Binary: KEY 130-133, code CODES 18-24,
Birthdays: BBB 115-116, EQEA 100-105, chances of sharing LUCKY 125-128, What are the chances of 366 strangers all having different birthdays?, The Day of the Huntrodds!
Bisecting lines and angles: MM2 113-119, lines SAVSH 22-26, angles SAVSH 26-27
Blue moon: EQEA 44
Brackets: PHX 22-24, AWAR 167-168
Buoyancy: DMEAS 146-149
Caesar Shift Code: Caesar Shift
Cake: dividing fairly SAVSH 51-60
Calculator: getting sin, cos, tan values FANG 75-87, tricks MOM 11-38
Calculators (online): Area calculator, LCD and HCF, Prime Number calculator,
Time calculator,
Quadratic calculator, The Factoriser Calculator.
Calculus: A bit of Calculus!. There is an introduction and explanation in "Newton and His Falling Apple" by Kjartan Poskitt. differential calculus 56-63, integral calculus 92-94.
Calendar: BBB 109-116, EQEA 49-57, Babylonian Julian Gregorian DMEAS 159, tricks MOM 58-62, The Calendar Trick
Cancelling fractions: MANDV 56-63
Cards (playing cards): chances LUCKY 128-136, chances MMoE 75-77, tricks MOM 63-99, algebra trick MM1 116-124, The Chances of Card Hands, How many different ways can you put a pack of cards in order?
Centred Hexagon Numbers: KEY 60-62, PSAUS 19
Chance: LUCKY (whole book), MMoE 81-84, The Chances of Card Hands, The National Lottery Odds The Day of the Huntrodds!
Chaos Maths: Sierpinski's Triangle MMoE 80
Chess board curiosities: MMoE 7-8, 85-87, chess and dominoes MM2 14-23, How many squares on a chess board?, The Knight's Move Magic Square, The Eight Queens Chess Puzzle, The Chess Board Illusion
Kjartan Poskitt's Fun Maths Videos
Chocolate bar: how many snaps to break EQEA 78
Chords (of circles): SAVSH 106-113, PSAUS 155
Chunking: SOS 116-117
Cicidas: MMoE 17, The Cicadas 17-year Life Cycle
CIRCLES: ASAS 49-57, SAVSH 100-120, PSAUS 152-157, The Names of Bits of Circles Quiz, How to find the centre of a circle using a book, How to make a Circle into a Square
Clock arithmetic: EQEA 31-36
Clocks: MM1 60-71
Codes: CODES (whole book), Secrets of Codes
Coefficients: PHX 12, Pascal coefficients PHX 100-107
Coin tossing: LUCKY 18-23, 40-43, 44-60, 63-66, 68, 70-77, MMoE 73-74
Coin Tricks/Problems: MOM 114-132, DBB 52-53, 82, The Coin Pyramid (Tower of Hanoi), The 6 Coin Circle Problem, The Twelve Coin Balance Problem (and solution)
Combinations: LUCKY 78-103, PSAUS 106-108, The Unknown (Combinations) Formula
Compass: bearings and navigation FANG 181-196
Compasses: circles, bisecting lines and angles MM2 111-119
Cone: volume of cone, area of sloping side PSAUS 172 What is the volume of a cone?
Conversions: PSAUS 195, angles dms calculator button FANG 141
Conway calendar: EQEA 56-57
Co-ordinates: PHX 128-142
Cos: FANG 67-68, 60º, 0º, 90º, 45º FANG 93, cosine formula FANG 119-123
Crescent areas: PSAUS 158-161
Cube (solid): formulas PSAUS 10, 143-146, the 11 nets EQEA 81, The Magical Self-Assembling Cube!
Cube (x3): KEY 57-60, curve on graphs PHX 142
Cube Number Triangles
Squared Triangle and Cube Numbers
Cyclic Quadrilateral: SAVSH 103-105
Cycloid: MMoE 45-47
Day of Week algorithm: PSAUS 95-100
Decimal fractions: SOS 172-178, MANDV 100-111
Decimal point: SOS 160-165, AWAR 163
Degree (angle measurement): ASAS 20-21
Density: DMEAS 145-146, PSAUS 201
Diagonals: PSAUS rectangle 10, 13, polygons 123, 124, cuboids 144, Diagonals of Polygons (with proof)
Dice: LUCKY 23-25, 104-125, SAVSH 128-133, MMoE 78, puzzle DBB 100-102, The Devils Dice Puzzle
Kjartan Poskitt's Fun Maths Videos
Difference of two squares: KEY 50-52, PHX 108-110
Dimension 1D 2D 3D: MMoE 50-51, MM2 33-43, 3D Noughts and Crosses Game
Divine Proportion (or Golden Ratio): KEY 26-31, MMoE 54-55
Division: SOS 104-132, AWAR 107-134 When will numbers divide by 7,11,13? When will numbers divide by 1-10?
Dms: calculator button FANG 141
Dodecahedron: PSAUS 149, SAVSH 121, 127, 131, 135, make MOM 181-186,
Dodecahedron page
Dominoes: BBB 59-75, MM2 13-23
Doubling the cube: MMoE 33-35.
Dragon Curve: MOM 157-162
Drawing: triangles FANG 38-45
e = 2.71828182845904523536... : KEY 178-183, PSAUS 92, The Growth Formula and Elvis Impersonators
Egg: how to draw MMoE 37
Egyptian fractions: MANDV 86-87
Einstein, Albert: PSAUS 65, 69
Ellipses: ASAS 185-201, SAVSH 137-147, how to draw SAVSH 141-143, formulas PSAUS 180-182, The Area of an Ellipse and Volume of Ellipsoids, The Ellipse Page including how to find the centre and foci
Elvis Presley: 2043 - The Year That We All Turn Into ELVIS!
Equations: PHX 19-45, quadratic PHX 56-66, simultaneous PHX 147-156, names of different types MM1 94,
Equilateral triangle: SAVSH 31, how to draw with ruler and compasses SAVSH 74 how to fold from paper SAVSH 96
Eratosthenes: Sieve of Eratosthenes MMoE 14, Circumference of the Earth MMoE 37, Sieve of Eratosthenes
Estimating: AWAR 153-162
Euclid: BBB 28-29
Euler: solids formula SAVSH 123, e,i,PI formula KEY 186, Euler's Formula and Euler's Identity
Exam tips: GCSE Slips and Tips (exam help)
Expanding (brackets): PHX 48-52
Factorial: AWAR 166-167, LUCKY 79-81
Factorising: algebra PHX 48-52, into prime factors MANDV 45-48, 53-55, The Factoriser Calculator
Facts (pathetic): KEY 9-16, 191-192, The Most Pathetic Facts in Maths
February 30th: EQEA 52
Fermat's Last Theorem: KEY 66-70
Fibonacci: MMoE 56-60, KEY 17-41, Fibonacci trick KEY 40-41, PHX 78, formula PSAUS 203, Fibonacci and Nature
Finger Times Tables: KEY 119-122, Finger Times Tables
Fixed point theorem: MMoE 67
Flexagons: MOM 100-113, How to make a Triflexagon video version, How to make Flexagons step by step version
Four 4's: Sunny's Four 4's Challenge
Four colour map theorem: MMoE 68-69, Four Colour Map Theorem
Formulas: PSAUS whole book, EQEA 23
Fortune Telling with numbers: KEY 71-76
Fractal: MOM 162
Fractions: SOS 141-191, MANDV whole book, AWAR 112-114,
Friday 13th: EQEA 55-56
Games: chances of various results in card and board games MMoE 81-84
G.C.S.E Slips and Tips
g Gravity: PSAUS 55, 63. For a lot more information on gravity and forces, see "Isaac Newton and His Apple" by Kjartan Poskitt 69-85, 154-157
Geometry: Catriona Shearer's Gorgeous Geometry Puzzles!
Geometry set: FANG 12-19, ASAS 24-34
Giant people-eating spider: why you can't get one EQEA 86-90
Gigameter: DMEAS 48
Golden Ratio: KEY 26-31, MMoE 54-55
Golomb Rulers: MMoE 48-49, How a Golomb Ruler can make you famous for ever
Gradients (on graphs): PHX 134
Graham's number: EQEA 127
Graphs: x and y axis and how to plot for equations PHX 132-143
HCF (Highest Common Factor): MANDV 52, LCD and HCF calculator
Hemisphere: PSAUS 171
Hexagon: how to draw SAVSH 73, how to fold from paper SAVSH 97, tessalation SAVSH 85,
Horizon: how far away? EQEA 37-41
Huntrodds Day: Sept 19th
Hurricanes: Hurricane measurements, speed, strength and names
Hypotenuse: FANG 60
i : KEY 183-186, square root of i The Research Lab
Icosahedron: PSAUS 149, SAVSH 121, 125, 127, 131
Illusion: MM2 43, Illusions Home Page
Imperial units: DMEAS 30-45
Infinity: KEY 7-9, 188-190
Inscribed circle: PSAUS 118
INT function (integer division): PSAUS 97
Interest (money): PSAUS 82-94.
International date line: MMoE 27-28
Irrational numbers: KEY 164-173
Isosceles triangle: SAVSH 11, 31-32
Jokes: The Murderous Maths Jokes Page
Kaprekar: KEY 115
Kepler: PSAUS 62
K-Puzz Logic Puzzles: K-Puzz Page
Kjarposko Puzzles: KAK, The Dreaded Kjarposkos
LCD or LCM (Lowest Common Denominator / Multiple): MANDV 64-73, 78-80, LCD and HCF calculator
Light year: FANG 155-156, DMEAS 21, EQEA 62
Line, area, volume: MM2 24-54
Locus: SAVSH 21-22
Logic Problems: DBB, how to make a liar tell the truth EQEA 64-68, Dolly's Rush Hour, Luigi's Outside Table
Long Division: SOS 117-130, AWAR 123-126,
Lottery: LUCKY 93-94, The National Lottery Odds
Lucky numbers: KEY 76-77
Magic Squares: MOM 48-62, MM1 103-106, How to make 5x5 and 7x7 Magic Squares, How to make 4x4 Magic Squares
Magic Tricks: MOM, A few tricks from The Magic Of Maths
Mathematicians: MM1 81-97
Mean: averages MANDV 124-156
Measurements: DMEAS whole book, MM2 44-54
Median: MANDV 146-149
Mersenne Primes: KEY 100-103, 142-144 The Research Lab
Metric System: DMEAS 45-51, prefixes EQEA 58-60
Mirror numbers: MM2 107-108
Mobius strip: BBB 96-100, MM2 74-80, MMoE 40-41,
Kjartan Poskitt's Fun Maths Videos
Mode: MANDV 143-146
Modulus (MOD function): PSAUS 98, CODES 148-149, The Modulus 105 Trick
Money: PSAUS 70-94, interest and e KEY 180-183, history AWAR 135-144
Moon: how fast does it move, siderial and synodic months EQEA 42-43
Multiplication: SOS 80-98, AWAR 93-101, Russian Peasant Multiplication EQEA 17
Music: MMoE 61-64, How many different tunes can you play on a piano? EQEA 7-12, Why do some musical notes sound awful together?, How do guitar strings make different notes?, The sounds of SIN and SQUARE waves
Mutually exclusive outcomes: LUCKY 106
Nanometer: DMEAS 47
Nets (of solids): ASAS 174-178, SAVSH 128-136 the 11 nets of a cube see: The Research Lab
Newton: PSAUS 64-65. For a lot more information on forces, see "Isaac Newton and His Apple" by Kjartan Poskitt 144-157
Nim games: MOM 118-123
Noughts and crosses: 4-dimensional MMoE 53, 3D noughts and crosses
Numbers: KEY, The link between Squared Triangle and Cube Numbers
Number facts: The Most Pathetic Facts in Maths
Number tricks: MOM 133-156, The 7-11-13 trick, The Impossible Guess, The Missing Digit Trick, Riverboat Lil's Mindreader trick
Octahedron: PSAUS 149, SAVSH 121. 125, 127, 133-134
Odd and Even numbers: AWAR 15-16
Odds: LUCKY 38-39, 153-161
Origami: ASAS 155-162
Palindrome numbers: MM2 107-108
Parabola: x2 graphs PHX 139- 144
Paradox: BBB 25-28
Parallax: FANG 150, 153
Parallelogram: PSAUS 134
Parallel lines: how to draw FANG 18
Parsecs: FANG 155-158
Pascal's Triangle: MMoE 72-80, for coefficients of (a+b)n PHX 100, probability LUCKY 61-77, combinations LUCKY 96-99, Pascal's Triangle How to get Fibonacci series see THE RESEARCH LAB
Pendulums: PSAUS 68
Penrose Roger: tiles SAVSH 90-91, The Penrose Chickens and Tiles
Pentagon: how to fold from paper SAVSH 97-98
Pentagonal Number: PSAUS 19
Pentominoes: MM2 16-20
Percentages: SOS 171-178, PSAUS 72, MANDV 112-117
Perfect Numbers: KEY 136-146
Perimeter: ASAS 118-128, PSAUS 12, 116, MM2 99-106, EQEA 75-77
Permutations: PSAUS 103-105, LUCKY 81-88, DBB 46-47
Perpendicular bisector: ASAS 32,95 SAVSH 22-26
PI: ASAS 52-57, KEY 174-178, PSAUS 15, 150-152, LUCKY 143-147, MM2 89-94, EQEA 24
Picometer: DMEAS 47
Pizza cutting: PSAUS 31, Chopping Pizzas
Planets: distance from sun MMoE 90
Plato: ASAS 167-170
Poker hands (chances of): MMoE 84, Chances of different hands of playing cards
Polygons: ASAS 129-154, SAVSH 56-99, PSAUS 116-126, tan area formula FANG 126-128, The Research Lab
Powers: BBB 117-121, AWAR 168-169, MM1 15-18
Prime factors: MANDV 43-48
PRIME NUMBERS: explanation MANDV 40-44, SOS 133-137, KEY 90-112, MMoE 12-17, MM1 46-51, Sudoku prime SUD 126, The SUDOKU Prime, use in codes CODES 148-149, The Prime Numbers Trick, The Prime Counter Mersenne Primes KEY 100, 142 The Research Lab Sieve of Eratosthenes MMoE 14, Sieve of Eratosthenes, How to write a Massive Prime Number!
Prince Rupert's Cube: EQEA 82
Profit: PSAUS 70-74
Proportion: FANG 30-31
Protractor: DMEAS 120-121, FANG 16-17
Pursuit curves: MMoE 44
Puzzles: DBB whole book, SUD, KAK, Puzzle Page, Dreaded Kjarposkos, Murderous Brainbending Puzzles also see "Sam Loyd" below
Pyramid: PSAUS 10, 146 What is the volume of a pyramid? With proof.
Pythagoras: MMoE 19-22, MM2 81-88 construction theorem proof SAVSH 148-159, EQEA 25-28, cut and paste theorem proof EQEA 26, ASAS 202-207 How do guitar strings make different notes?
Quadratics: solving equations and formula PHX 53-66, PSAUS 138, Solving Quadratics by Completing the Square, Quadratic calculator
Queens: The Eight Queens Chess Puzzle
Radians: DMEAS 124
Ramsey Theorem: EQEA 127-129
Ratios: FANG 30-37, trigonometry FANG 59
Rectangle: formulas PSAUS 10-13 How to turn a Rectangle into a Square of the same area
Reducing fractions: MANDV 49-51
Regions: Surprising Regions Formula
Regular Solids: SAVSH 121-136, formulas for surface area and volume PSAUS 149,
Regular Solids - formulas for volumes
Research Lab: THE RESEARCH LAB
(With answers to a very wide variety of odd maths questions!)
Rhombus: PSAUS 135
Richter Scale: Earthquake measurements
Right angle: MM1 72
Right angled triangles: MM2 81-88
Roman numerals: MM1 27-31
Rough sums: SOS 198-206
Rounding off: AWAR 145-152, MM1 126-129
RSA codes: CODES 145-157
Rubik's Cube: EQEA 83
Russian Peasant Multiplication: EQEA 17
Sam Loyd: The Sam Loyd Sliding Block Puzzle, Sam Loyd's Get Off The Earth Puzzle, Sam Loyd's Eight Queens Puzzle
Sampling: LUCKY 149-152
Scale: FANG 20-29
Scoville rating: Hotness of chilli pepper measurement
Scrambled Message Code: Scrambled Messages
Sector: PSAUS 156
Segment: PSAUS 157
Semicircle: right angle SAVSH 12-13,
Semiperimeter: PSAUS 116
Set Square: FANG 17-18
Shadow Stick: DMEAS 66
Sierpinski's Triangle: MMoE 80
Sieve of Eratosthenes: MMoE 14, Sieve of Eratosthenes
Significant digits/figures: AWAR 145
Simulaneous Equations: graph solving PHX 136-137, elimination and substitution PHX 147-156
Sin: FANG 60-66, 60º, 0º, 90º, 45º FANG 88-92, getting values by drawing FANG 94-96, sin formula PSAUS 120, sin formula FANG 114-118, triangle area formula FANG 128-130
Sine wave: FANG 165-174, The sounds of SIN and SQUARE waves
Skewes' number: EQEA 125
Sohcahtoa: FANG 71
Space: size of moons, planets, stars MMoE 88-93
SPEED: PSAUS 38-60, BBB 76-92, MM2 61-73
Sphere: PSAUS 10, 170-172 packing into a box EQEA 150-151
SQUARE (shape): how to draw with ruler and compasses SAVSH 74-76, how to fold SAVSH 94, dividing a square into smaller squares all of different sizes EQEA 29.
SQUARE (x2): KEY 43-56
Square Pyramid Numbers: KEY 63-64, PSAUS 20
Square Roots: EQEA 18-22, How to work out Square Roots without a calculator, square root of i The Research Lab
Stamps: formula for number of ways of tearing from a sheet PSAUS 21-24, 196-197,
Matthew Sheeran's Amazing Stamps Formula!
Standard Form: DMEAS 56-63, MM1 130-135
Star: distance away FANG 147-158, sizes of MMoE 93
Subtraction: SOS 35-54, AWAR 53-70
Sudoku: how many possible grids? SUD 122-127, The SUDOKU Prime
Symmetry: MM1 136-141
Tan: FANG 69-71, 45º FANG 94
Tangents: SAVSH 114
Teachers: Teacher Resource Page
Temperature: DMEAS 169
Tessalation: ASAS 150-154, SAVSH 88-91, MM1 19-21
Testing for factors: MANDV, KEY 108-111, Testing if numbers divide by 11, 7 or 13, The 11 Test
Tetrahedral Numbers: KEY 62-63, PSAUS 19, 90
Tetrahedron: PSAUS 148-149, SAVSH 121, 125, 127, 131, 133
Thales: BBB 21, SAVSH 12-13,
Think of a number tricks: MOM 39-47, PHX 79, A few tricks from The Magic Of Maths
Tic-tac-toe: 4-dimensional MMoE 53, 3D TTT puzzle
Time: DMEAS 158-167, see Speed, Acceleration, Pendulums
Times tables: SOS 55-80, AWAR 71-92
Kjartan Poskitt's Fun Maths Videos
Topology: MMoE 38-42, bridge crossing and drawing problems MM2 136-145 fluid handcuffs EQEA 142-143
Torus: PSAUS 173-174, volume The Research Lab
Trancindental numbers: KEY 174-183
Trapezium: PSAUS 139-142,
Calculating the Area of a Trapezium without the height!
TRIANGLES: ASAS 35-48, SAVSH 39-65, formulasPSAUS 126-134 constructing FANG 38-45, sin area formula FANG 128-130
Triangle Numbers: MM2 123-130, KEY 54-56, PSAUS 17-18, 21, 89, MMoE 18, The link between Squared Triangle and Cube Numbers, KEY 64-65
Triangulation: FANG 133-136
Tricks: DBB, PHX 74-90, Professor Fiendish's Tricks and Games
Trigonometry: FANG (whole book), PSAUS 121
Trisecting an angle: MMoE 30, How to Trisect an Angle
Unit fractions: PSAUS 192
Units of measurement: DMEAS 168-174, Some Unusual Units
Universe: size of EQEA 61
Vector: EQEA 69-72
VIDEOS: Kjartan Poskitt's Fun Maths Videos
Vigenere Code System: Vigenere Grids
Volume: measuring DMEAS 127-133
Vulgar Fractions: SOS 148-152
Wallpaper: Download your Murderous Maths Wallpaper for your computer desktop.
Waves: sin cos tan FANG 165-180
Weights: smallest number needed for balance scales EQEA 93-97
Y intercept (on graphs): PHX 135
Yahtzee: chances of throwing combinations MMoE 83
Zero: invention of 0 MM1 35-36, impossible proof PHX 157
Murderous Maths Main Index Page
For education and classroom
computer solutions we recommend
|
The Murderous Maths website is hosted by
These people sorted out all sorts of fiddly problems for us quickly and at no extra charge,
and we would highly recommend them to anyone.
|
