ELI5: Explain Like I'm 5

Disk algebra

Disk algebra is a way of doing math with things called "disks." Imagine you have a bunch of round, flat objects like coasters or frisbees. These are disks. In disk algebra, we can use these disks to represent numbers and do calculations.

Let's start with a simple example: adding two numbers. To represent a number, we can use a disk with a dot in the center. The dot represents 1. So if we have a disk with one dot, that represents the number 1. If we have a disk with two dots, that represents the number 2, and so on.

Now let's say we want to add 2 and 3 together. We can do this by stacking two disks with two dots on top of three disks with one dot. When we stack them, we just put them on top of each other like a tower. The result is a stack of five disks, which represents the number 5.

We can do more complicated calculations, too. For example, if we want to multiply two numbers, we can stack disks in a grid. Let's say we want to multiply 3 and 4. We would stack three disks in a row, and then four disks in a column. Then we would count up the dots where the rows and columns intersect. In this case, we would have 12 dots, which represents the number 12.

One cool thing about disk algebra is that it works not just for whole numbers, but also for fractions and negative numbers. To represent a fraction, we can use a smaller disk inside a larger one, with the number of dots representing the numerator and denominator, respectively. To represent a negative number, we can use a disk with a dot on the bottom instead of the top.

Overall, disk algebra is a fun and visual way to learn about math and do calculations. By using disks to represent numbers, we can make abstract concepts more concrete and easier to understand.