by Serhiy Grabarchuk Jr
Six matchsticks are placed on a table as is shown.
What is the minimum number of matchsticks which have to be moved in order to get 5 squares out of the 6 matchsticks? Overlapping of the matchsticks is allowed.
The minimum number is 3. Moving them to the new positions as is shown in the illustration leads to 4 small squares and 1 big square to appear.