The range of representable normalized numbers in the floating point binary fractional representation in a 32-bit word :
bais = 2n-1 = 28-1 = 128
Number 1 in normalized format = 0.0000000....23times = 20-128 = 2-128
Maximum Number 1111111..22 times = 0.111111...23 times = (1- 2-23 ) * (2255-128) = (1- 2-23 ) * (2127)