You have learn how to subtract binary numbers. However, this method is not suitable to implement in computer hardware. In this topic, you will learn how, using the same principles of binary addition, binary subtraction can be done. This method called Two's Complements can be easily be performed by computer hardware.

By the end of this lesson, you will be able to perform Binary Subtraction using Two Complements.

Estimated duration : 20 min

Lesson 1 of 4: Two’s Complement

Let's see how to obtain a Binary Number using Two's Complement. Click on the video below.

https://www.youtube.com/watch?v=sJXTo3EZoxM&t=364s

Let's review what you have learn from the video.

Two's Complement

Let's review the basic steps to obtain Two's Complement of a binary number.

1. Obtain a One Complement by  inverting each digit of the binary number.

2. Obtain a Two's Complement by adding a 1 to the One Complement

Example

Express 7 decimal in binary using  Two's Complements.

Lesson 2 of 4: Binary Subtraction Using Complements

Now we know what is Two's Complement, let's see how we can use it to do binary subtraction. There are 2 cases where the methods will differ slightly.