Adding and Subtracting on an Open Number Line within 20

This video tutorial teaches how to add and subtract numbers within 20 using an open number line. It covers the basics of addition and subtraction, explains the commutative property, and provides practical examples of using a number line for these operations. The tutorial emphasizes that while addition is commutative, subtraction is not, and demonstrates this through examples.

Why is subtraction not commutative? Provide an example.

Describe the process of subtracting 14 minus 6 on an open number line.