IEEE 754 addition wrong result floating point numbers I want to add two IEEE 754 numbers.
I followed the steps to add two 754 numbers. However the result it not correct.
Number 1:
S:0
E:01111111
M:11111111111111111111111
Number 2:
S:0
E:01111111
M:00000000000000000000000
Here is my calculation:

The site http://weitz.de/ieee/ gives this result:
S: 0
E: 10000000
M: 10000000000000000000000
in my calculation the mantissa is 01111...
Why?
You forgot the implicit leading 1 in the mantissa. The mantissa is not 23 bits, it's 24 bits with a 1 as the leading bit.