Let's simplify the given absolute values.

a) $|10| = 10$

The absolute value of 10 is 10 because it's already a positive number.

b) $|-4| = 4$

The absolute value of $-4$ is 4 because the absolute value turns negative numbers into their positive counterparts.

Do you have any further questions on this? Here are some related questions for practice:

1. What is $|-15|$?
2. Simplify $|25|$.
3. What is the absolute value of $-9$?
4. Calculate $|-100|$.
5. Simplify $|0|$.

Tip: Absolute values always return the non-negative version of the number inside.