Let's use today to have a practise of our numbers 0-20.
Can they count from 0-20?
Can they count back from 20-0?
Can they recognise random numbers under 20?
Can they put the numbers in the correct order?
Can they write all the numerals in the correct direction?
Can say what one more / one less than a given number is?
Can they count on from a number under 20?