It helps a lot. You should add a question mark that shows some explanation, and perhaps an example. Some random ideas: Here in Argentina we put the intermediat

It helps a lot. You should add a question mark that shows some explanation, and perhaps an example. Some random ideas: Here in Argentina we put the intermediate numbers in horizontal lines, so it's hard to guess what is happening. With the explanation and some tries I got the idea. Perhaps repeat at the bottom [p2][p1][p0]x[q2][q1][q0]=number, replacing p... and q... with the selected numbers It would be nice that the correct digits in the result number at the bottom are painted green and the wrong red. I want confetti when I win!!! :) Auto-prop is too strong and ruins most of the fun. But perhaps it's too hard without auto-prop. The only strategy I found if to use guessing a.k.a brute force. Important: When a slot has zero options, it should show "0" instead of "<= 10". Important: When a number is selected and I want to change it, let's say 7 to 3, it should be possible to do this in a single step. Now it needs two steps: "7 -> clear" and "clear -> 3". The idea is that when I click on the seven, the pop up window should show the 7 in one color and all the other valid options in other like 2, 3, 9. So I can click directly on the 3.