The common-core math standards require that students learn the standard algorithm for multi-digit adding and subtracting—you know, the process in which you line the numbers up vertically to add or ...

How to subtract tens from two-digit numbers Bill and Bernie use labelled balloons to show subtractions of 10 from several two-digit numbers which are less than 100. Bernie thinks of a number and Bill ...

Your child continues to use tape diagrams as a visual tool to solve word problems. Your child continues to use tape diagrams as a visual tool to solve word problems. Now, he solves for an unknown in ...

Column subtraction is a way of subtracting larger numbers. It is called column subtraction, because you write one number underneath the other, using place value to sort the tens and ones in separate ...

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 ...

The National Council of Teachers of Mathematics is a public voice of mathematics education, providing vision, leadership, and professional development to support teachers in ensuring mathematics ...