I have these set of montessori cut out numerals and was playing another activity with N when we accidentally created a new activity out of it.
I saw how N was happily forming 2 digit numbers using the cut out numerals and decided to play a game with him. I would shout out a 2-digit number for N to form using the numerals. For instance, i say 'mummy wants forty-seven!' and he'd scramble to find the digits '4' and '7' and put them side by side to form the number. It was kind of challenging for him at first though he could pick out the correct numbers but would display them wrongly. For instance he would arrange it as '74' instead of '47'. After a few tries, he finally got it!