An appearing act

Cut out and reassemble the pieces. Can you explain what happens?
Exploring and noticing Working systematically Conjecturing and generalising Visualising and representing Reasoning, convincing and proving
Being curious Being resourceful Being resilient Being collaborative

Problem



This resource is part of "Dotty Grids - Exploring Area"


You may wish to print out some dotty paper.

Take an 8 by 8 square, and cut it up like this:

Image
An appearing act


Rearrange the pieces to make a 13 by 5 rectangle:

Image
An appearing act


It seems we can use the same pieces to make two shapes with different areas!

Can you explain why?

Can you perform this “magic trick” by splitting squares of other sizes in a similar way?

Which squares are least obvious?

What patterns are there in the square sizes?