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 ...

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Hello, lovely learners. My name's Miss White and I'm so excited to teach you today. For this lesson you ...

When you are adding larger numbers, it’s often better to use a written method. Column addition is a good written method to add one number to another. It involves putting the digits of each number into ...