Have you ever read a storybook where the characters have different adventures and do things in different order? The Bible is a special book that has stories about people and events that happened a long time ago. Some people believe that every single story in the Bible actually happened exactly like it was written, and they use a special way of counting time to figure out when everything happened. This is called biblical literalist chronology.
To help explain how it works, let's pretend a book has a story about a boy who went on a trip and did five things. In the story, it says he left on Monday, went to the park on Tuesday, went to the zoo on Wednesday, came back on Thursday, and bought ice cream on Friday.
Now, if someone believed that the story was telling the truth and everything happened in the order it was written, they would count the days starting from Monday. So Monday would be Day 1, Tuesday would be Day 2, and so on.
Using this same idea, biblical literalist chronology counts time in the Bible by looking at different stories and adding up all the ages of the people mentioned and the years between different events. They believe that the Bible is like a timeline, and they can figure out when everything happened by reading it and counting the days and years.
Some people like learning about the Bible in this way because it helps them understand the stories better and feel like they know what really happened. Other people think it's okay to read the Bible as stories that teach important lessons, even if they might not have all really happened exactly like that. There isn't really a right or wrong way to read the Bible, it just depends on how each person wants to understand and learn from it.