Mathematics according to the Zhenya Katz system is gaining momentum. Already in kindergartens, they are engaged in it, and clubs are opening, and mathematical camps for schoolchildren are arranged. More and more people are imbued with this system, because it is non-trivial and gives good results. The author herself says that her main task is to captivate the child with this complex science, and children really get carried away! I have seen how schoolchildren attending these classes can tell from one glance at the picture whether the rope will be tied or there will be no knot; assimilate and themselves can explain literally on the fingers the principle of a binary code; using a sheet of paper and a few cuts with scissors, they create absolutely believable three-dimensional models like in panorama books. And most importantly, everything looks as if they were born with this knowledge!