Number 0 should be done with objects first until they get the idea of 0 as a number.
Theoretically each of these 19 representations can be matched with 18 representations. So the variety is enormous. Practically the 7 different representations (leaving out the arithmetic) can be matched against the other 6.
The matching can be done either physically with “flash cards” or on a computer screen. Ideally it can be done physically in the classroom and at home on the screen.