That's the idea at the end about presenting the "sticky notes" as products of primes. Assuming you can't factor the primes yourself, you can be given the whole grid of those products and then interactively ask for the factors or a pair of them. The requestor can't give an alternative factorization (ie. make up a color on the spot) since each number can only be factored one possible way and its easy to verify.

I really liked this part that shows all the numbers up front, and none of them change during the reveal step.

I think it would present better if introduced as "To show that there's no cheating going on behind the scenes, we will..."

Yeah I agree it could be presented clearer. Maybe make the analogy of multiplying the factors together and "covering with a post it" more explicit

You're right. That does cover it. I was playing with my kid and I didn't get it at first.

I might use smaller factors then.