Byrne's Euclid is a strange Victorian edition of Euclid using colours instead of letters. I'm not sure whether it's really easier for children, but it is interesting to look at. Some excellent person made a classy online edition.
Logic can be used to solve problems, but it cannot suggest which problems to try. No one has ever formalized significance. To recognize what is significant you need a certain amount of experience, plus that elusive quality: intuition.
On the other hand, one of the actors from the best Canadian show right now is going to star in a Marvel superhero movie with Tony Leung of In The Mood For Love/Bullet In The Head fame, and Awkwafina of Queefing Like A Chief fame. When she became a big movie star she removed the original video, which is humanity's loss.