Keywords - Calculating in your head, operations, times tables.

Purpose - Learning how to calculate in your head in a playful way.

Pre-requisites - Knowing how to count, knowing the 4 operations.

Description - It is played in pairs. The trainer delineates an area that serves as a stage for the duel. The two participants go to the centre of the stage back to back like in a western gunfight. When the trainer gives the go-ahead, the two duellers take 3 steps in the opposite direction. At the end of the third step the trainer calls out an operation to be calculated mentally. The duellers can turn around and mimic shooting the adversary only when they can give the answer of the operation assigned by the trainer. The person who “shoots” the correct answer first wins the duel and remains standing while the adversary that has been “hit” falls to the ground and is eliminated. After the elimination a new dueller enters the game.

Duration - About 30 minutes.

Variations - Depending on the level of competitiveness desired in the game, the duelling couples can be changed at each round or the person who gives the correct answer can remain.

Observations - It is important to evaluate whether participants are ready to compete with each other or whether a climate of competition could inhibit those weaker at calculating in their head. To reduce the tension of the competition, it is important that the trainer maintain a playful atmosphere.

The difficulty of the operations proposed should be evaluated to reflect the capacity of the participants.