The Addition Rule is really useful when we want to figure out the chances of two different events happening. Let’s break it down:

• What It Is: The Addition Rule helps us find the chance of either event A or event B happening. You can think of it as adding up the chances of each event separately.

• Simple Formula: If the events cannot happen at the same time (we call these mutually exclusive), you just add their chances together:
  $P(A \cup B) = P(A) + P(B)$

• For Events That Overlap: If A and B can happen together, we have to take away the chance that they both happen at the same time:
  $P(A \cup B) = P(A) + P(B) - P(A \cap B)$

Using this rule, we can figure out more complicated situations, like what happens when you roll a die or draw cards. This way, we can see how likely different outcomes are!