All children sit in a cirlce with the cards face down in the centre. Going around the cirlcle, each student is to pick up one card, then turn it over and show every one. If it is the card they are looking for, the child holds onto the card, and has another turn, if it is not the next number, the card is turned back over and the next child has a turn. The aim is to begin by finding number one, then two, three, four, etc. until all cards have been found in order.
Variations include, writing the word instead of the number for a literacy focus, counting back from 20, start by looking for number 20 then go backwards to 1, use any numbers that you are working with in the class.
You could use this with older students and the multiplication facts, or any basic facts, the idea would be to go from the smallest group to the largest.