Hi, Brian

Indeed it needs a constrain feature like i mentioned in the original post. But nephew only have Moi and love it so much that I won't 'spoil' him with other app which made we want to solve the quiz ONLY in Moi. Also, seems like you're much more smarter than me in math, so I can't understand much of your 'math talks' in your posts. But I appreciate much for the effort and please continue to do so if you please. :)

Cheers!