Step 1: You may start by figuring out the origins of the decimal number system in terms of units, tens, hundreds and so on.

Note: the decimal number system is based on ten because humans use their ten fingers to count. You should realize that the same process of weights is repeated for Binary and Hexadecimal systems.

Step 2: Follow the lesson notes (in the resource section) and try to list some examples of two-state devices such as lighting in computer labs, switches, air-condition units and a variety of on/off devices.

Note: Computers use the binary number system because they are electronic devices.

Step 3: The next interesting thing that you should be able to learn is why computers also use the hexadecimal number system.

Note: Hexadecimal number system is  a shorthand notation to shorten the lengthy binary numbers.

Step 4: follow the detailed lesson plan and find the examples to understand the use of the hexadecimal number systems, such as: the ‘blue screen of death’;  colour codes;  MAC and IPv6 addresses, address of memory locations; etc.

Step 5: Finally you can proceed by realising how the positional notation for the binary number system is used to determine the value of a binary number in decimal. 

Note: You will cover the conversions between the different number systems in Number Systems – Lesson 2: Converting between Decimal, Binary and Hexadecimal.