Position the lines so that they are perpendicular to each other. What can you say about the equations of perpendicular lines?
A jigsaw where pieces only go together if the fractions are equivalent.
A game for 2 or more people, based on the traditional card game Rummy.
If you have ten counters numbered 1 to 10, how many can you put into pairs that add to 10? Which ones do you have to leave out? Why?
Choose four different digits from 1-9 and put one in each box so that the resulting four two-digit numbers add to a total of 100.
There are three versions of this challenge. The idea is to change the colour of all the spots on the grid. Can you do it in fewer throws of the dice?
How many questions do you need to identify my quadrilateral?
