Can you complete this jigsaw of the 100 square?
Ben and his mum are planting garlic. Use the interactivity to help
you find out how many cloves of garlic they might have had.
Investigate what happens when you add house numbers along a street
in different ways.
Can you complete this jigsaw of the multiplication square?
Can you see how these factor-multiple chains work? Find the chain
which contains the smallest possible numbers. How about the largest
What do the numbers shaded in blue on this hundred square have in common? What do you notice about the pink numbers? How about the shaded numbers in the other squares?
Take a look at the multiplication square. The first eleven triangle
numbers have been identified. Can you see a pattern? Does the
Delight your friends with this cunning trick! Can you explain how
Can you describe this route to infinity? Where will the arrows take you next?
Where we follow twizzles to places that no number has been before.
Arrow arithmetic, but with a twist.
A loopy exploration of z^2+1=0 (z squared plus one) with an eye on
winding numbers. Try not to get dizzy!
Make the twizzle twist on its spot and so work out the hidden link.
Add powers of 3 and powers of 7 and get multiples of 11.
When is $7^n + 3^n$ a multiple of 10? Can you prove the result by two different methods?
Investigate powers of numbers of the form (1 + sqrt 2).
Alice thought very carefully about this problem.
Jamie and Nik described these transformations very clearly. However
the triangular challenges are still to be cracked!
We've received a clear solution to this problem from Alice, George,
Kyle, Tom, Nell and Alex.
Both Tiffany and Andrei sent in clear solutions to this problem.
In this article for teachers, Bernard Bagnall describes how to find
digital roots and suggests that they can be worth exploring when
confronted by a sequence of numbers.
This article for the young and old talks about the origins of our number system and the important role zero has to play in it.
This Sudoku puzzle can be solved with the help of small clue-numbers on the border lines between pairs of neighbouring squares of the grid.
Infinity is not a number, and trying to treat it as one tends to be a pretty bad idea. At best you're likely to come away with a headache, at worse the firm belief that 1 = 0. This article discusses the different types of infinity.
In this article we shall consider how to solve problems such as
"Find all integers that leave a remainder of 1 when divided by 2,
3, and 5."