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 ...

You can add or subtract numbers in lots of different ways. You can use number lines, number bonds, fact families, 10 squares and counters, or even just writing the numbers down. Sometimes it is faster ...

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 ...

This study examined Korean second and third graders' understanding of multidigit addition and subtraction and particularly their ability to explain the trading required when a column sum of the ...

Scarlett Howard received funding for this project from The Company of Biologists and the Australian Government. Adrian Dyer and Jair Garcia do not work for, consult, own shares in or receive funding ...