# Videos for iPods. etc. (in .m4v format)

## Right click the links and then "Save file as..." or "Save link as..."

### Ages 11 - 14, Years 7 - 9

Linear sequences - nth term in the form an + b

Bisecting angles - using ruler and compasses only

Perpendicular bisectors - using ruler and compasses only

More constructions - equilateral triangle, perpendicular from a point on a line, perpendicular from a point to a line

Trial and improvement - for solving equations approximately

### Ages 14 - 16, Years 10 - 11, GCSE Foundation

Percentage multipliers - percentage increases and decreasesas decimal multiplying numbers

Upper and Lower Bounds 1 - introduction

Direct and inverse proportion 1 - with example questions

Inequalities - regions of graphs - combining inequalities

Simultaneous (systems of) equations 1 - adding equations

Simultaneous (systems of) equations 1a - adding or subtracting equations

Simultaneous (systems of) equations 3 - multiplying equations

Straight line graphs 1 - finding the gradient

Straight line graphs 2 - gradients and equations

Straight line graphs 3 - y-intercepts and equations

Circle theorems - isosceles triangles - one vertex at the centre

Circle theorems - angle in a semicircle is a right angle

Circle theorems - angle at the center is twice the angle at the circumference

Circle theorems - tangents - lengths and angles

Reflections 1 - how to draw and find the reflection line

Rotations 1 - how to draw and find the centre and angle

Translations 1 - - how to draw and describe using vector notation

Symmetry 1 - decribing combinations of symmetries as single transformations

Indices 1 - adding

Indices 2 - subtracting

Indices 3 - powers of powers

Indices 4 - zero and negative indices

Surds 1 - what are surds

Surds 2 - some basic rules of manipulation

Surds 3 - simplifying

Surds 4 - simplifying by rationalising the denominator 1

Similarity 1 - intro

Similarity 2 - distances - lengths and scale factors

Similarity 3 - areas

Congruent triangles 1 - introduction

Congruent triangles 2 - SSS - side, side, side

Congruent triangles 3 - SAS - side, angle, side

Congruent triangles 4 - AAS - angle, angle, side

Congruent triangles 5 - RHS - right angle, hypotenuse, side

Moving averages and trend lines 2 - extrapolating the trend

Probability tree diagrams 1 - independent events

### Ages 14 - 16, Years 9 - 11 - GCSE Higher

Upper and Lower Bounds 2 - bounds of harder calculations

Indices 5 - fractional indices

Indices 6 - exponential equations

Lengths and angles in cuboids - using Pythagoras and trigonometry

Direct and inverse proportion 2 - harder questions

Algebraic fractions 2 - simplifying

Algebraic fractions 3 - solving equations

Simultaneous (systems of) equations 3 - linear/quadratic

Simultaneous (systems of) equations 4 - linear/quadratic

Straight line graphs 4 - parallel and perpendicular lines 1

Straight line graphs 5 - parallel and perpendicular lines 2

Circle theorems - angle in a semicircle - PROOF

Circle theorems - angle at the center - PROOF

Circle theorems - alternate segment theorem

Histograms 1 - introducing frequency density

Histograms 2 - using frequency densities

Histograms 3 - a common style of question

Probability tree diagrams 2 - dependent events

### Ages 16 - 19, Years 12 - 13, A Level

Quadratic sequences - nth term

Cubic sequences - nth term

Algebraic Long Division - cubic expression divided by a linear one

Bubble Sort Algorithm - a worked example

Shuttle Sort (Insertion Sort) Algorithm - a worked example