Whenever my son has a new math teacher, I taught him to ask if he can change the base when reciting the times tables. For example the 12 times table in base 12

Whenever my son has a new math teacher, I taught him to ask if he can change the base when reciting the times tables. For example the 12 times table in base 12 is 10, 20, 30, 40 and so on. It usually gets a laugh or a tut before he has to do it the right way.