Fixed-point arithmetic is a way of storing numbers on a computer in a special way that allows us to do math with them. Instead of using the regular numbers we use in everyday life (numbers like 10 or 22), we use special "fixed-point" numbers, where the decimal point is fixed in a certain spot. For example, if we're using 4-digit fixed-point arithmetic, numbers would look like this: 512.3452. This means that the number 512.3452 is equal to 5.123452 (since the decimal point is "fixed" at the fourth digit). We can then use normal arithmetic operations (add, subtract, multiply, divide) on the fixed-point numbers, just like we could with regular numbers.