I started educating my child at age 1. By the time he entered Kindergarten he knew all his colors, shapes, count to 1000, ABC's lower and upper along with sounds, and at least 75 "popcorn" words. He also was well versed in simple science which he loved. He could do simple addition and subtraction, 2 digits in his head because I did not let him use paper. By the time he entered 4th grade he was reading at the 12th grade level and was doing 11th grade math. He graduated Highs cool with an honors degree and passed 8 AP (college) level classes and started college with over 30+ credits as a Sophomore. We as parents are responsible for educating our children, the School can only do so much.
I babysat a "poor" child for 2 weeks while his parents were out of the country for work training. I helped him with his homework, read with him, and fed him and his older sister before sending him and her home for the night to sleep. I got a call after 1 week because the school was going to call child protection services on the parents for leaving the country. I told them they couldn't because I was watching over them. I asked how they knew? Did the little boy tell? NO! He was able to read 3 books this week, he couldn't even usually read 1, so they knew he was coming to my house every day!
That is why I say it is a parents job to teach, without reinforcement at home, the child does not do well!