Common practice is memorising tables from 1 to 10.
However, research suggests that some tables are easier to learn than others, and also help derive facts of unfriendly numbers. Facts of 2, 5 and 10 are the easiest to learn, and kids would do well learning these before all the other ones.
Below is one such level which helps a child visualise 2 X 6, which is a fact of 2.
