If you have school age children, you really should know just what they're being taught in the classroom. The video below examines the "constructivist" math curriculum that has invaded public schools across the country, including New York City. "Everyday Math," around which much of the video centers, is the preferred math program of the City's Department of Education.
It's 15 minutes long, but well worth watching, even if you don't have kids in the public schools. Every single person to whom I've shown this video has been horrified by it and by what math education in the elementary grades has become.
Now it's your turn.