i think the binary is not rappresenting 88 value

[LorenzoPiombini]

in the explanation of SHA 256, when you say

Append 64 bits to the end, where the 64 bits are a big-endian integer representing the length of the original input in binary. In our case, 88, or in binary, “1011000”.

the value "1011000" is not 88 but is 176