# Why do computers use binary arithmetic

In electronics, a voltage level or current flow is a way to represent a value. For example, 5V volts or 0. The makers of electronic devices could, of course, assign any meaning that they want to different voltage values.

You would end up with 0. This means that when building an electronic device, it is most often desired to have the energy consumption as low as possible and to have a low voltage. Furthermore, electronic signals are not always very steady and can vary because of surrounding influences, like nearby internal circuits for other electronic devices. This might then lead to voltage levels where it gets difficult to distinguish which value it represents.

As a result, we cannot divide the 5V into 10 steps. The values could be misinterpreted. A computer might suddenly make wrong calculations because of random interference. This example of voltage ranges shows that it is necessary to have a safe range between two voltage levels in order to read the correct value with percent probability. There are additional methods on the software level to verify that data is read correctly, but this is out of the scope of this article.

Binary comes from the Latin language and means that something is composed of two things. Binary electronics are usually called digital electronics. Another major reason is because a lot more circuitry is needed to distinguish between more than two voltage levels. In the case of binary 11, there is a 1 in the first position, which equals 1 and then another 1 in the second position, so that equals 2.

As numbers get larger, new digits are added to the left. To determine the value of a digit, count the number of digits to the left of it, and multiply that number times 2. For example, for the digital number , to determine the value of the 1, count the number of digits to the left of the 1 and multiply that number times 2.

The total value of binary is 4, since the numbers to the left of the 1 are both 0s. Now you know how to count digital numbers, but how do you add and subtract them? Binary math is similar to decimal math. Adding binary numbers looks like that in the box to the right above. To add these binary numbers, do this: Start from the right side, just as in ordinary math. Write a 1 down in the solution area.

According to our rule, that equals 0, so write 0 and carry the 1 to the next column. Any time you have a column that adds up to decimal 3, you write down a 1 in the solution area and carry a 1. In the fifth column you have only the 1 that you carried over, so you write down 1 in the fifth column of the solution. Computers rely on binary numbers and binary math because it greatly simplifies their tasks.

Since there are only two possibilities 0 and 1 for each digit rather than 10, it is easier to store or manipulate the numbers. Computers need a large number of transistors to accomplish all this, but it is still easier and less expensive to do things with binary numbers rather than decimal numbers. The original computers were used primarily as calculators, but later they were used to manipulate other forms of information, such as words and pictures.