On a digital 24 hour clock, at certain times, all the digits are consecutive. How many times like this are there between midnight and 7 a.m.?
How many winning lines can you make in a three-dimensional version of noughts and crosses?
Identical squares of side one unit contain some circles shaded blue. In which of the four examples is the shaded area greatest?
There are six numbers written in five different scripts. Can you sort out which is which?
Charlie and Abi put a counter on 42. They wondered if they could visit all the other numbers on their 1-100 board, moving the counter using just these two operations: x2 and -5. What do you think?
Many numbers can be expressed as the difference of two perfect squares. What do you notice about the numbers you CANNOT make?
Can you dissect an equilateral triangle into 6 smaller ones? What number of smaller equilateral triangles is it NOT possible to dissect a larger equilateral triangle into?
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?
What is the largest number which, when divided into these five numbers in turn, leaves the same remainder each time?
