Математичний аналіз і диференціальні рівняння вивчаю САМ

Sorry for off-topic, I am considering about building an enlightening site for young students. Will probably begin with posting interesting information such as"It is impossible to lick your elbow."Please let me know if you know where I can find some related info such as right here

bigpersonatraveler.tumblr.com/
pleasantlyjoyfulkitten.tumblr.com/