Here is a part-whole model. Sometimes the model is rotated. It looks different, but it still has two parts and a whole. We can use this model to help us solve problems. We can put 4 things in one of ...

Solve real world problems with addition and subtraction within 1,000. Warm up with a Mystery Math Mistake as you add two 2-digit numbers using a decomposition strategy. Use visual models and place ...

Here you will find a video about addition and subtraction. Watch this, and then test your knowledge with a short quiz before exploring the rest of the collection. This section contains videos from our ...

“For some, common core is creating common confusion,” said education correspondent Rehema Ellis on a recent NBC News segment. The crux of the news piece was that parents are struggling to help their ...