When you are solving an addition calculation with a two-digit number, you need to think about tens and ones. A place value chart can help you to see the value of each digit in a number. For example, ...

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 ...

Addition and subtraction with regrouping using different strategies to solve. In this lesson, students go over addition and subtraction with regrouping using different strategies to solve. Today we ...

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 ...