And they add on the number line in order to subtract ... the way the standards teach subtraction. Students learn regrouping and the standard algorithm in 4 th grade.

It illustrates how zero is used in addition and subtraction, showing that adding or subtracting zero from another number does not change its value. The video also discusses zero as a placeholder ...

In the past, many of us learned subtraction by following the traditional algorithm, which involved stacking two numbers and some form of “borrowing” over digits. Traditional Subtraction ...