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 ...

Subtraction from a two-digit number Two cartoon characters use labelled balloons to show subtractions of 10 from several two-digit numbers of less than 100. One character thinks of a number and the ...

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 ...

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 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 ...

“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 ...