Curated OER
How Do You Subtract by Regrouping?
This simple video provides a great way to review the concept of subtraction with regrouping. There are visual representations of the tens and ones to aid in understanding. An excellent resource.
Khan Academy
Khan Academy: Subtracting 10s Using Place Value
Demonstrates how to subtract 40 from 65 using drawings of base ten cubes to represent 1s and 10s. [2:37]