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 ...

Children's solutions to simple addition and subtraction word problems were studied in a 3-year longitudinal study that followed 88 children from Grades 1 through 3. The children were able to solve the ...

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 ...