### Sprouts Explained

### Breaking the Equation ' Empirical Argument = Proof '

### Air Nets

### Geometry and Gravity 2

### Impossible Sandwiches

### The Bridges of Konigsberg

### Yih or Luk tsut k'i or Three Men's Morris

### Advent Calendar 2011 - Secondary

### What does it all add up to?

### A Knight's Journey

### Picturing Pythagorean Triples

### To Prove or Not to Prove

### Some Circuits in Graph or Network Theory

### An introduction to proof by contradiction

### Proof: A Brief Historical Survey

### Binomial Coefficients

### Mega Quadratic Equations

### Iffy logic

### Network Trees

### There's a limit

### Unit Interval

### Common Divisor

Can you find out what numbers divide these expressions? Can you prove that they are always divisors?

### Summing geometric progressions

### Dalmatians

### Impossible sums

### Difference of odd squares

### The Converse of Pythagoras

Can you prove that triangles are right-angled when $a^2+b^2=c^2$?

### Always Perfect

### Curve fitter

This problem challenges you to find cubic equations which satisfy different conditions.

### Sixational

### Always Two

Find all the triples of numbers a, b, c such that each one of them plus the product of the other two is always 2.

### Back fitter

10 graphs of experimental data are given. Can you use a spreadsheet to find algebraic graphs which match them closely, and thus discover the formulae most likely to govern the underlying processes?

### Quad in Quad

### Calculating with cosines

### Iff

### Pent

### Proof Sorter - Quadratic Equation

### Kite in a Square

### Leonardo's Problem

### A long time at the till

### Telescoping Functions

### Where do we get our feet wet?

### Why stop at Three by One

### Modulus Arithmetic and a solution to Differences

### Sums of Squares and Sums of Cubes

### Transitivity

### Modulus Arithmetic and a solution to Dirisibly Yours

### Continued Fractions II

### Fractional Calculus III

### Sperner's Lemma

### Euler's Formula and Topology

### A computer program to find magic squares

### An Alphanumeric

### Powerful properties

### The kth sum of n numbers

### Euclid's Algorithm II

### An introduction to number theory

An introduction to some beautiful results in Number Theory.

### On the Importance of Pedantry

### Fixing It

### Big and small numbers in physics - Group task

### Sixty-Seven Squared

### Napoleon's Hat

Three equilateral triangles ABC, AYX and XZB are drawn with the point X a moveable point on AB. The points P, Q and R are the centres of the three triangles. What can you say about triangle PQR?