Quarter the Cross

At the end of last year, the MTBoS (Math(s) Twitter Blog-o-Sphere) introduced me to this very interesting task: you have a cross made of four equal squares, and you are supposed to colour in exactly 1/4 of the cross and justify why you know it's a quarter. I call it "Quarter the Cross".

Illustration: A blue cross made of five equal squares, with one square in the centre and one square attached to it on each side.  Text: Quarter the Cross Colour in one quarter of this cross. You have to be sure it's exactly a quarter.

You can read the rest of this blog post, and four other related posts, in PDF form here

      The titles of the five posts in the series are:

      • Quarter the Cross (2016)
      • A Day of Maths: Quarter the Cross (2016)
      • David Butler and the Prisoner of Alhazen (2016)
      • Quarter the Cross: Colouring (2020)
      • Quarter the Cross: Connect the Dots (2020)

      Some resources linked from this post:

      Tagged in Isnt maths cool, One Hundred Factorial, Thoughts about maths thinking