Videos:

• What is an Algorithm?

• Addition with Base Ten Blocks

• The Standard Addition Algorithm

• Alternative Addition Algorithms

• The Partial Sums Algorithm

• When Units Aren’t Base Ten

• Understanding Subtraction

• Subtraction Algorithms

When adding two numbers using the U.S. Standard Addition Algorithm, we start in the rightmost place value. We add the digits, and regroup any results that are 10 or larger. We continue this process, slowly moving from right to left.

When subtracting two numbers using the U.S. Standard subtraction Algorithm, we start in the rightmost place value. We subtract the digits, and regroup when a subtraction isn’t possible or would result in a negative number. . We continue this process, slowly moving from right to left.