Let S1 = 1 , S2 = 2 + 3, S3 = 4 + 5 + 6 ,........ Calculate S17.

Can you figure out how sequences of beach huts are generated?

Play around with the Fibonacci sequence and discover some surprising results!

First of all, pick the number of times a week that you would like to eat chocolate. Multiply this number by 2...

Make some loops out of regular hexagons. What rules can you discover?

Choose four consecutive whole numbers. Multiply the first and last numbers together. Multiply the middle pair together. What do you notice?

What would you get if you continued this sequence of fraction sums? 1/2 + 2/1 = 2/3 + 3/2 = 3/4 + 4/3 =

Can you see how to build a harmonic triangle? Can you work out the next two rows?

Think of a number, add one, double it, take away 3, add the number you first thought of, add 7, divide by 3 and take away the number you first thought of. You should now be left with 2. How do I. . . .

Surprising numerical patterns can be explained using algebra and diagrams...

Jo has three numbers which she adds together in pairs. When she does this she has three different totals: 11, 17 and 22 What are the three numbers Jo had to start with?”

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?

The squares of any 8 consecutive numbers can be arranged into two sets of four numbers with the same sum. True of false?

I added together the first 'n' positive integers and found that my answer was a 3 digit number in which all the digits were the same...

Arrange the numbers 1 to 16 into a 4 by 4 array. Choose a number. Cross out the numbers on the same row and column. Repeat this process. Add up you four numbers. Why do they always add up to 34?

Take any pair of two digit numbers x=ab and y=cd where, without loss of generality, ab > cd . Form two 4 digit numbers r=abcd and s=cdab and calculate: {r^2 - s^2} /{x^2 - y^2}.

Many numbers can be expressed as the difference of two perfect squares. What do you notice about the numbers you CANNOT make?

The sum of the numbers 4 and 1 [1/3] is the same as the product of 4 and 1 [1/3]; that is to say 4 + 1 [1/3] = 4 � 1 [1/3]. What other numbers have the sum equal to the product and can this be so. . . .

A little bit of algebra explains this 'magic'. Ask a friend to pick 3 consecutive numbers and to tell you a multiple of 3. Then ask them to add the four numbers and multiply by 67, and to tell you. . . .

Account of an investigation which starts from the area of an annulus and leads to the formula for the difference of two squares.

Can you explain what is going on in these puzzling number tricks?

Think of a two digit number, reverse the digits, and add the numbers together. Something special happens...

Some students have been working out the number of strands needed for different sizes of cable. Can you make sense of their solutions?

When number pyramids have a sequence on the bottom layer, some interesting patterns emerge...

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. . . .

Pick a square within a multiplication square and add the numbers on each diagonal. What do you notice?

Robert noticed some interesting patterns when he highlighted square numbers in a spreadsheet. Can you prove that the patterns will continue?

If a two digit number has its digits reversed and the smaller of the two numbers is subtracted from the larger, prove the difference can never be prime.

Can you find a rule which connects consecutive triangular numbers?

How good are you at finding the formula for a number pattern ?

Try entering different sets of numbers in the number pyramids. How does the total at the top change?

A task which depends on members of the group noticing the needs of others and responding.

Pick the number of times a week that you eat chocolate. This number must be more than one but less than ten. Multiply this number by 2. Add 5 (for Sunday). Multiply by 50... Can you explain why it. . . .

Use the numbers in the box below to make the base of a top-heavy pyramid whose top number is 200.

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?

Can you find a rule which relates triangular numbers to square numbers?

The sums of the squares of three related numbers is also a perfect square - can you explain why?

Show that if you add 1 to the product of four consecutive numbers the answer is ALWAYS a perfect square.

Think of a number and follow the machine's instructions... I know what your number is! Can you explain how I know?

Think of two whole numbers under 10, and follow the steps. I can work out both your numbers very quickly. How?

Show that all pentagonal numbers are one third of a triangular number.

This article explains how to make your own magic square to mark a special occasion with the special date of your choice on the top line.

If you know the perimeter of a right angled triangle, what can you say about the area?

Crosses can be drawn on number grids of various sizes. What do you notice when you add opposite ends?

If you take a three by three square on a 1-10 addition square and multiply the diagonally opposite numbers together, what is the difference between these products. Why?

Can you show that you can share a square pizza equally between two people by cutting it four times using vertical, horizontal and diagonal cuts through any point inside the square?

Can you explain why a sequence of operations always gives you perfect squares?