This problem offers you two ways to test reactions - use them to investigate your ideas about speeds of reaction.
Imagine a machine with four coloured lights which respond to different rules. Can you find the smallest possible number which will make all four colours light up?
Here is a machine with four coloured lights. Can you develop a strategy to work out the rules controlling each light?
Here is a machine with four coloured lights. Can you make two lights switch on at once? Three lights? All four lights?
To investigate the relationship between the distance the ruler drops and the time taken, we need to do some mathematical modelling...
Can you suggest a curve to fit some experimental data? Can you work out where the data might have come from?
William discovered a couple of rules that apply to all Celtic Knots.
Go to last month's problems to see more solutions.
In this article for teachers, Alan Parr looks at ways that mathematics teaching and learning can start from the useful and interesting things can we do with the subject, including modelling scientific enquiry.
This game challenges you to locate hidden triangles in The White Box by firing rays and observing where the rays exit the Box.