Comedian Louis C.K. recently went on a social-media rant about the Common Core State Standards and testing, as my colleague Catherine Gewertz blogged this week. Within the Twitter barrage of ...

Count forwards and backwards in eights using this counting stick. If we know the answer to a multiplication number sentence or multiplication fact we can work out the answer to an unknown number ...

Subtraction is taking away one number from another. When you subtract it gives you the difference between two numbers. Here are 7 blocks. If you take away three blocks, how many are left? There would ...