There is nothing more basic than number facts. Every student needs to know them and every relief teacher should have this in their repertoire. This is one activity that I use on every one of my relief teaching days. You can cater for any class and any student. Knowing number facts is a prerequisite to math success. Educationists dropped the ball for a few years and number facts lost favour with the educational thinking of the day. But now, number facts are back in vogue.