An story and 3 questions

My oldest and his little public schooled friend, who is a month younger, were talking the other day. My son says: "2 plus 2 plus 1 equals 5." His friend says "No, it doesn't." The boys are kindergarten-age.

Question 1: What do kids learn in kindergarten? Obviously not math. My son's friend can't read, either. This is a serious question: I'm a second generation homeschooler.

Question 2: This little boy went to preschool last year. What do kids learn in preschool? Clearly not math or reading.

Question 3: If kids don't learn anything academic in preschool or kindergarten, why do their parents send them? What's different than daycare?