Semi-regular tessellations combine two or more different regular polygons to fill the plane. Can you find all the semi-regular tessellations?
When dice land edge-up, we usually roll again. But what if we
Is this a fair game? How many ways are there of creating a fair game by adding odd and even numbers?
Create some shapes by combining two or more rectangles. What can
you say about the areas and perimeters of the shapes you can make?
Interior angles can help us to work out which polygons will tessellate. Can we use similar ideas to predict which polygons combine to create semi-regular solids?
Photocopiers can reduce from A3 to A4 without distorting the image.
Explore the relationships between different paper sizes that make
Take three whole numbers. The differences between them give you
three new numbers. Find the differences between the new numbers and
keep repeating this. What happens?
Do you want to understand what your chances are of winning the
lottery? Then take a look at these solutions.
Go to last month's problems to see more solutions.
Jenny Piggott reflects on the event held to mark her retirement
from the directorship of NRICH, but also on problem solving itself.
These models have appeared around the Centre for Mathematical Sciences. Perhaps you would like to try to make some similar models of your own.
Unmultiply is a game of quick estimation. You need to find two numbers that multiply together to something close to the given target - fast! 10 levels with a high scores table.