Watch the episode 'Magic cups!' by MathXplosion.
(This video was developed with Kristy from Minchinbury PS, Stephanie from Parramatta PS and Alishia from Sylvania Heights PS)
Transcript coming soon.
You will need:
3 cups, or 3 of the same object (forks, spoons, markers or Lego blocks, etc.)
paper
3 different coloured markers, pens or pencils.
Set up your three cups (or forks, spoons, etc.) So they are orientated like this:
Notice how the middle cup is facing down and the two outside cups are facing up.
Your challenge is to flip pairs of cups, in exactly three moves, to have them all facing down.
Flip one pair of cups and record your move.
Flip a second pair of cups and record your move.
For the third time, flip a pair of cups and record your move!
Once you've found one way of flipping pairs of cups in exactly 3 moves, see if you can find another way!
Revise your recording by sharing your thinking in a table. You could use the ideas shared with you in the video.
What does the starting position need to be to get the trick to work in exactly 4 moves using 4 cups? Or 5 cups in 5 moves?