Hansen's problem

Okay, so there's this guy named Hansen and he had a problem.

You know how sometimes when you try to do something and it's really hard or you just can't figure it out? That's kind of what Hansen's problem was like.

Hansen's problem was about math. Do you remember when we talked about numbers and how we can add and subtract them? Well, Hansen was trying to do some really complicated math problems with lots and lots of numbers.

But the problem was that he wasn't really sure if the answers he was getting were correct. It was like he was trying to solve a really big puzzle, but he couldn't be sure if he had all the right pieces.

So, Hansen came up with a solution to his problem! He created a new way of thinking about math problems, and he called it "interval arithmetic".

Interval arithmetic is kind of like a special way of doing math where you're not just thinking about one number at a time. Instead, you're thinking about a whole range of numbers that the answer could be in.

Let's say we're trying to add two numbers together: 3 and 4. With interval arithmetic, instead of just thinking about the answer being 7, we think about all the numbers that could be the answer, anywhere from 6 to 8.

And that's the basics of Hansen's problem and how he solved it with interval arithmetic!