PC Hardware A Beginner’s Guide

Converting Decimal to Binary

Here’s a quick way to convert a decimal number into a binary number:

1. Divide the decimal number by 2 and keep the answer. Write down the
   remainder (you may want to start writing down the remainders on the
   right side of the paper); it will be either a 1 or a 0.


2. Divide the answer by 2 and record the remainder to the left of the
   first remainder.


3. Repeat step 2 until the number in the answer is either a 1 or a 0 and
   record it to the left of the last remainder.

For example, if you used the above procedure to convert the number 2,469 to

a binary number, it would go like this:

1. 2,469 divided by 2 equals 1,234 with a remainder of 1


2. 1,234 divided by 2 equals 617 with a remainder of 0


3. 617 divided by 2 equals 308 with a remainder of 1


4. 308 divided by 2 equals 154 with a remainder of 0


5. 154 divided by 2 equals 77 with a remainder of 0


6. 77 divided by 2 equals 38 with a remainder of 1


7. 38 divided by 2 equals 19 with a remainder of 0


8. 19 divided by 2 equals 9 with a remainder of 1

Chapter 3: Microprocessors^43

Bit Power of Two Decimal

120 1

221 2

322 4

423 8

524 16

625 32

726 64

827 128

Table 3-1. The Bit Values in a Byte