The children’s badges read 红卫兵 “Red Guard” and the image on the floor reads, 我爱北京天安门 “I love Beijing Tiananmen.” The poem of the same name in the top righthand corner is below.
A silkscreened armband with the characters 红卫兵,Red Guard printed on it. See similar armbands here. Below is the same armband that was handstitched, most likely by a family member.