Absolute Subtraction Mistake

Algebra Level 2

Lazy Liz doesn't like absolute values notation, and often drops them from her equations. She always writes

$|a-b| = a-b.$

How many of the $11 \times 11$ ordered pairs of integers $(a, b)$ , each of which are between 0 and 10 inclusive, are there, such that

$|a-b| = a-b?$