What do you do if you make a mistake during a presentation? Well, everyone makes mistakes. Relax. Don't put so much pressure on yourself. But here's the key. If you make a mistake don't tell anyone. Just sweep it under the rug. Because realize your audience doesn't know what your next point was typically. They don't know what you left out.
The big problem for most people when they make a mistake is not the mistake itself. It's sort of holding up a big sign, hey everybody I screwed up. Woe is me. I feel bad. Don't tell everybody. Don't put this look on your face like, oh gosh, or duh. Don't beat yourself up in front of your audience, because that's what they remember.
If you make a mistake and it's something obvious of a factual nature, you meant to say billion and you said trillion, then don't call it to everyone's attention. Just correct yourself briefly. If it's a mistake that nobody will notice or mind just keep on going. They won't notice it. For example, about 15 seconds ago I said sent. I meant to say said. But I didn't cry, and whine, and hold up a big sign, and apologize, and say cut take two. I just kept going.
Because the way people hear information is different from how they read information. If you put the wrong word in text it stands out. If you occasionally have a wrong word when you're speaking to people it's typically not noticeable.
You want to act like you can't believe how well this presentation is going. If you do make a mistake either ignore it or correct yourself without apology or fanfare, and then keep on going. When you're done put a smile on your face and act like you just gave the best speech ever without a single mistake. Do that, and no one will remember your mistakes.