Pebbles and Tamarind Seeds

Pebble games (the odd, even, bust game played with tamarind seeds, or shells or pebbles): Start the game with an equal number of pebbles to the two children. Ask them to play 5 rounds of the game and report back as to who won (the one with the largest number or the smallest number wins, based on the rules agreed to by both the players). Check the number of pebbles they have and verify if the claim of who won is correct based on the number and the rule of play. Do a few times with a few different pairs of students. Based on this it is easy to conclude if the children know what odd/even numbers are, larger than or smaller than or equal to relations between numbers (and actual objects) and the simple ability to count from 1 to X, where X is the sum of the pebbles given to the children.