The sum of any two of the numbers 2, 34 and 47 is a perfect square. Choose three square numbers and find sets of three integers with this property. Generalise to four integers.
A, B & C own a half, a third and a sixth of a coin collection. Each grab some coins, return some, then share equally what they had put back, finishing with their own share. How rich are they?
Show that for natural numbers x and y if x/y > 1 then x/y>(x+1)/(y+1}>1. Hence prove that the product for i=1 to n of [(2i)/(2i-1)] tends to infinity as n tends to infinity.
If x + y = -1 find the largest value of xy by coordinate geometry, by calculus and by algebra.
Given a set of points (x,y) with distinct x values, find a polynomial that goes through all of them, then prove some results about the existence and uniqueness of these polynomials.
Take a complicated fraction with the product of five quartics top and bottom and reduce this to a whole number. This is a numerical example involving some clever algebra.
Find all positive integers a and b for which the two equations: x^2-ax+b = 0 and x^2-bx+a = 0 both have positive integer solutions.
Take any two numbers between 0 and 1. Prove that the sum of the numbers is always less than one plus their product?
Relate these algebraic expressions to geometrical diagrams.
Given any two polynomials in a single variable it is always possible to eliminate the variable and obtain a formula showing the relationship between the two polynomials. Try this one.
Find the largest integer which divides every member of the following sequence: 1^5-1, 2^5-2, 3^5-3, ... n^5-n.
By considering powers of (1+x), show that the sum of the squares of the binomial coefficients from 0 to n is 2nCn
A point moves around inside a rectangle. What are the least and the greatest values of the sum of the squares of the distances from the vertices?
A polite number can be written as the sum of two or more consecutive positive integers. Find the consecutive sums giving the polite numbers 544 and 424. What characterizes impolite numbers?
Janine noticed, while studying some cube numbers, that if you take three consecutive whole numbers and multiply them together and then add the middle number of the three, you get the middle number. . . .
To find the integral of a polynomial, evaluate it at some special points and add multiples of these values.
Can you find the value of this function involving algebraic fractions for x=2000?
Find all the solutions to the this equation.
Four jewellers share their stock. Can you work out the relative values of their gems?
The nth term of a sequence is given by the formula n^3 + 11n . Find the first four terms of the sequence given by this formula and the first term of the sequence which is bigger than one million. . . .
Eulerian and Hamiltonian circuits are defined with some simple examples and a couple of puzzles to illustrate Hamiltonian circuits.
Freddie Manners, of Packwood Haugh School in Shropshire solved an alphanumeric without using the extra information supplied and this article explains his reasoning.
Investigate the sequences obtained by starting with any positive 2 digit number (10a+b) and repeatedly using the rule 10a+b maps to 10b-a to get the next number in the sequence.
A serious but easily readable discussion of proof in mathematics with some amusing stories and some interesting examples.
Here the diagram says it all. Can you find the diagram?
This article invites you to get familiar with a strategic game called "sprouts". The game is simple enough for younger children to understand, and has also provided experienced mathematicians with. . . .
An article about the strategy for playing The Triangle Game which appears on the NRICH site. It contains a simple lemma about labelling a grid of equilateral triangles within a triangular frame.
When if ever do you get the right answer if you add two fractions by adding the numerators and adding the denominators?
Prove that you cannot form a Magic W with a total of 12 or less or with a with a total of 18 or more.
The sums of the squares of three related numbers is also a perfect square - can you explain why?
A composite number is one that is neither prime nor 1. Show that 10201 is composite in any base.
Show that if you add 1 to the product of four consecutive numbers the answer is ALWAYS a perfect square.
Can you convince me of each of the following: If a square number is multiplied by a square number the product is ALWAYS a square number...
Kyle and his teacher disagree about his test score - who is right?
This follows up the 'magic Squares for Special Occasions' article which tells you you to create a 4by4 magicsquare with a special date on the top line using no negative numbers and no repeats.
Some diagrammatic 'proofs' of algebraic identities and inequalities.
Find the positive integer solutions of the equation (1+1/a)(1+1/b)(1+1/c) = 2
Can you rearrange the cards to make a series of correct mathematical statements?
An inequality involving integrals of squares of functions.
Try to solve this very difficult problem and then study our two suggested solutions. How would you use your knowledge to try to solve variants on the original problem?
I want some cubes painted with three blue faces and three red faces. How many different cubes can be painted like that?
By proving these particular identities, prove the existence of general cases.
Given that a, b and c are natural numbers show that if sqrt a+sqrt b is rational then it is a natural number. Extend this to 3 variables.
Some puzzles requiring no knowledge of knot theory, just a careful inspection of the patterns. A glimpse of the classification of knots and a little about prime knots, crossing numbers and. . . .
Given that u>0 and v>0 find the smallest possible value of 1/u + 1/v given that u + v = 5 by different methods.
A introduction to how patterns can be deceiving, and what is and is not a proof.
These proofs are wrong. Can you see why?
Advent Calendar 2011 - a mathematical activity for each day during the run-up to Christmas.
Explore a number pattern which has the same symmetries in different bases.
Which of these roads will satisfy a Munchkin builder?