If you teach middle or high school math - I highly recommend time looking through the lessons. They are amazing! All lessons use common core standards with real world problems. I have no idea if they cost $ or how much $ - This lesson - How Sharp Is The iPhone 5′s Retina Display?
Dan Meyer, math teacher extraordinaire, gives continual examples of what math education must look like once we we accept that students should be approached at their level and encouraged to think deeply about solving interesting problems.