How would you judge a competition to draw a freehand square?
Explore the properties of combinations of trig functions in this open investigation.
What's the chance of a pair of lists of numbers having sample
correlation exactly equal to zero?
You might like to play the factors and multiples game before attempting this investigation, which can be taken to many levels of complexity.
Write down a selection of positive whole numbers less than 100 in some positions of your choice on a large blank piece of paper.
Now, draw lines (not necessarily straight) which join each number in the selection with all of the factors and multiples of the number in the selection.
For your selection and arrangement of numbers, can you draw lines so that none cross?