I used to teach maths, albeit only up to age 16, and found that the reason many pupils struggled with calculations was that they did not know the tables off by heart. We knew them all by the age of 8, chanting them by rote. This can be fun for young kids, especially when given individual little treats for being able to chant a table correctly. Similarly we learnt the alphabet by the age of 5 by chanting it rhythmically in a sing-song voice which I still remember. I recall one of the older tutors on my PGCE course, who was not over-enamoured of modern educational theory, saying, "My motto is 'learn first, understand later' ". This advice has always stood me in good stead.