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 ...

“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 ...

Students put all of their addition and subtraction skills together to solve equations. In this lesson, students put all of their addition and subtraction skills together to solve equations. Julia ...

The present paper describes the success, the methods (mental, informal written, standard algorithm) and the strategies of informal written arithmetic to be observed when 300 elementary students worked ...

Karen C. Fuson, Diana Wearne, James C. Hiebert, Hanlie G. Murray, Pieter G. Human, Alwyn I. Olivier, Thomas P. Carpenter and Elizabeth Fennema Researchers from 4 projects with a problem-solving ...

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 ...