Converting a Denary Number to 8-Bit Binary

A denary number is a normal number we use every day. A binary number only uses 1s and 0s.

8-bit binary means your answer must have exactly 8 digits, like 01001101.

Step 1: Know the 8-bit place values

Each position in an 8-bit number has a value:

Bit position	1st	2nd	3rd	4th	5th	6th	7th	8th
Value	128	64	32	16	8	4	2	1

Example: Convert 77 to 8-bit binary

Start at 128 and work down the place values:

1. 128 fits into 77? No → write 0
2. 64 fits into 77? Yes → write 1
   New total: 77 − 64 = 13
3. 32 fits into 13? No → write 0
4. 16 fits into 13? No → write 0
5. 8 fits into 13? Yes → write 1
   New total: 13 − 8 = 5
6. 4 fits into 5? Yes → write 1
   New total: 5 − 4 = 1
7. 2 fits into 1? No → write 0
8. 1 fits into 1? Yes → write 1

Step 3: Final 8-bit number

Value	128	64	32	16	8	4	2	1
Bit	0	1	0	0	1	1	0	1

77 in 8-bit binary = 01001101

Quick Summary

• Write the place values: 128, 64, 32, 16, 8, 4, 2, 1
• Start with the largest value and work down
• If the value fits → write 1 and subtract it
• If it doesn’t fit → write 0
• After all 8 values, you have your 8-bit binary number