Khan Academy: Arithmetic Properties: Inverse Property of Addition

Simple idea that multiplying by a numbers multiplicative inverse gets you back to one

This video explains the associative law of addition by writing an expression in a different ways.

This video introduces and demonstrates the concept of addition of integers using a number line. Practice problems are available. [5:32]

Video first explains and gives examples of identity matrices. Then explains what an inverse matrix is and shows how to calculate the inverse of a 2x2 matrix. [14:14]

The final segment in the Khan Academy's series on function inverses. Similar to the previous video, this segment does another example for finding the inverse of a quadratic function. Again the instructor explains the need for restraints...

This video demonstrates the inverse property of addition. Practice problems are available. [2:59]

This video shows the inverse property of multiplication and its relation to division. Practice problems are available. [3:16]

This video explains the identity property of zero by substituting values into an expression. Practice problems are available. [4:46]

This video explains the associative law of addition by writing an expression in a different way. Practice problems are available. [2:10]

This video explains the identity property of multiplication. Practice problems are included. [1:24]