Page 8    Perfect Numbers
Page 8    Prime numbers visually
Page 15  The Missing Dollar Paradox
Page 21  Difference between two dates

Chapter 3 - Fractions

Page 46    Left-handedness
Page 53    Adding fractions

 
Chapter 5 - Ratios and Rates

Page 106   Colour mixing (RGB) (1)
Page 106   Colour mixing (RGB) (2)   

Chapter 6 - Approximations, standard form and estimation

Page 114    When are zeros significant?
Page 121   US National Debt Clock
Page 121   World population clock
Page 124   Standard form converter
Page 124   The scale of the universe

Chapter 7 - Formulae and substitution

Page 138   Pyramid numbers (sums of squares) (1)
Page 138   Pyramid numbers (sums of squares) (2)

Chapter 11 - Two pairs of brackets

Page 203   Difference of two squares

Chapter 12 - Two-dimensional Graphs

Page 222   The Body-Mass Index Calculator

Chapter 13 - Graphs using rules from algebra

Page 240   Straight-line grapher from rule(1)
Page 240   Straight-line grapher from rule(2)

Chapter 14 - The metric system, scales and tables

Page 258  Metric length conversions
Page 261  Ferris wheel - metric conversion challenge
Page 265  Is midday 12 am or 12 pm?

Chapter 15 - Area and perimeter of polygons

Page 289    Area of parallelograms
Page 289    Area of trapeziums
Page 291    Honey, I've shrunk the area!

Chapter 16 - Circles - circumference and area

Page 302   Pi to one million decimal places
Page 302   Pi to more decimal places than you will ever need 
Page 302   The Greek alphabet

Chapter 17 - Volume and surface area

Page 316   Surface area and volume of cuboids
Page 328   Prism calculator

Chapter 18 - Angles 1 - intersecting and parallel lines

Page 340   Security Sensor question part 2d
Page 346   Sum of angles of a triangle
Page 353   Alternate angles and angles in a triangle

Chapter 19 - Angles 2 - Polygons

Page 374   Exterior angles of a polygon
Page 380   Tessellation town
Page 380   The tessellator
Page 380   Tessellation links
Page 382   Tetrominoes on a chessboard
Page 385   Grids for colouring in tessellations

Chapter 20 - Three dimensions

Page 390   The Klein bottle
Page 390   The missing corner cube
Page 391   Platonic solids
Page 399   Side views (1)
Page 399   Side views (2)
Page 401   The pentagonal potato slice

Chapter 21 - Pythagoras

Page 406   Pythagoras demonstration
Page 406   Three squares
Page 419   The spider and the fly

Chapter 23 - Trigonometry 2 - Calculating any side length

Page 446   SOH-CAH-TOA mnemonics
Page 455   The moving cuboctahedron

Chapter 25 - Construction and loci

Page 469   Perpendicular bisector
Page 470   Perpendicular to a line from a point not on the line
Page 471   Perpendicular to a line at a point on the line
Page 474   Perpendicular bisectors of a triangle
Page 477   Loco for Loci Desmos by Dan Meyer

Chapter 27 - Transformations 1 - Symmetry and conguence

Page 494   The Diamond 16 Puzzle
Page 503   Frieze patterns


Chapter 29 - Working with data

Page 560   Boxplots

Chapter 32 - The statistical enquiry cycle

Page 597   CensusAtSchool

Chapter 33 - Probability

Page 619   The racing cars
Page 620   Tongue-rolling