Material Required: Chart paper, paper clips, pen.
Dominoes are blocks made up of two squares. The activity consists of filling up a given square with dominoes. A chessboard is put before the students and they are asked how many dominoes are required to cover the chessboard. Now two opposite corners of the chess board are covered with black paper. How many dominoes are now needed to cover the chessboard? Ask the students to try and cover the chessboard with dominoes which have been cut out beforehand.
A square of 6<math>\times</math>6 and another of 4<math>\times</math>4 are available for the students to try out a similar exercise with them. Ask the students to reason out why it is impossible to cover the boards when two opposite squares are blanked out.