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Here is a Sudoku with a difference! Use information about lowest common multiples to help you solve it.
My measurements have got all jumbled up! Swap them around and see if you can find a combination where every measurement is valid.
Do you notice anything about the solutions when you add and/or subtract consecutive negative numbers?
Use the differences to find the solution to this Sudoku.
The clues for this Sudoku are the product of the numbers in adjacent squares.
Pick a square within a multiplication square and add the numbers on each diagonal. What do you notice?
Can you find the values at the vertices when you know the values on the edges?
This shape comprises four semi-circles. What is the relationship between the area of the shaded region and the area of the circle on AB as diameter?
Imagine a large cube made from small red cubes being dropped into a pot of yellow paint. How many of the small cubes will have yellow paint on their faces?
It's easy to work out the areas of most squares that we meet, but what if they were tilted?
Choose a couple of the sequences. Try to picture how to make the next, and the next, and the next... Can you describe your reasoning?
Think of a number and follow the machine's instructions... I know what your number is! Can you explain how I know?
The sums of the squares of three related numbers is also a perfect square - can you explain why?
When number pyramids have a sequence on the bottom layer, some interesting patterns emerge...
My two digit number is special because adding the sum of its digits to the product of its digits gives me my original number. What could my number be?
Show that if you add 1 to the product of four consecutive numbers the answer is ALWAYS a perfect square.
There are four children in a family, two girls, Kate and Sally, and two boys, Tom and Ben. How old are the children?
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?
Caroline and James pick sets of five numbers. Charlie tries to find three that add together to make a multiple of three. Can they stop him?
I'm thinking of a number. My number is both a multiple of 5 and a multiple of 6. What could my number be?
This is an interactivity in which you have to sort the steps in the completion of the square into the correct order to prove the formula for the solutions of quadratic equations.
Some diagrammatic 'proofs' of algebraic identities and inequalities.
Think of two whole numbers under 10, and follow the steps. I can work out both your numbers very quickly. How?
The items in the shopping basket add and multiply to give the same amount. What could their prices be?
There are lots of different methods to find out what the shapes are worth - how many can you find?
Liam's house has a staircase with 12 steps. He can go down the steps one at a time or two at time. In how many different ways can Liam go down the 12 steps?
Charlie likes tablecloths that use as many colours as possible, but insists that his tablecloths have some symmetry. Can you work out how many colours he needs for different tablecloth designs?
How many winning lines can you make in a three-dimensional version of noughts and crosses?
Can you produce convincing arguments that a selection of statements about numbers are true?
Find the missing angle between the two secants to the circle when the two angles at the centre subtended by the arcs created by the intersections of the secants and the circle are 50 and 120 degrees.
Play the divisibility game to create numbers in which the first two digits make a number divisible by 2, the first three digits make a number divisible by 3...
Take a triangular number, multiply it by 8 and add 1. What is special about your answer? Can you prove it?
Take any prime number greater than 3 , square it and subtract one. Working on the building blocks will help you to explain what is special about your results.
It is impossible to trisect an angle using only ruler and compasses but it can be done using a carpenter's square.
Four identical right angled triangles are drawn on the sides of a square. Two face out, two face in. Why do the four vertices marked with dots lie on one line?
Take any two numbers between 0 and 1. Prove that the sum of the numbers is always less than one plus their product?
In 15 years' time my age will be the square of my age 15 years ago. Can you work out my age, and when I had other special birthdays?
Can you guarantee that, for any three numbers you choose, the product of their differences will always be an even number?
Join the midpoints of a quadrilateral to get a new quadrilateral. What is special about it?
Take any four digit number. Move the first digit to the end and move the rest along. Now add your two numbers. Did you get a multiple of 11?
If it takes four men one day to build a wall, how long does it take 60,000 men to build a similar wall?
15 = 7 + 8 and 10 = 1 + 2 + 3 + 4. Can you say which numbers can be expressed as the sum of two or more consecutive integers?
Can you create a Latin Square from multiples of a six digit number?
Find the largest integer which divides every member of the following sequence: 1^5-1, 2^5-2, 3^5-3, ... n^5-n.
Explore the continued fraction: 2+3/(2+3/(2+3/2+...)) What do you notice when successive terms are taken? What happens to the terms if the fraction goes on indefinitely?
Is the mean of the squares of two numbers greater than, or less than, the square of their means?
Three points A, B and C lie in this order on a line, and P is any point in the plane. Use the Cosine Rule to prove the following statement.
Can you see how this picture illustrates the formula for the sum of the first six cube numbers?