This sounds like you're asking about a binary floating <span>point format, though I'm not positive because of the </span> <span>vocabulary you use. I interpret "characteristic" to mean </span> <span>"exponent" and "significand" as "fraction" (or "mantissa"). </span>
<span>If that's true, then you've described: </span>
<span>Note that there are other possible interpretations (for </span> <span>example, a base-16 exponent). </span>
<span>Since I'm assuming a binary exponent, we can use the same </span> <span>trick that IEEE 754 floating point standard does, and assume </span> <span>an "implicit" leading "1" to the fraction portion. This </span> <span>trick means that the fractional part will be between </span> <span>the following numbers (in base 2): </span>
<span>1.00000000000000000000 (1 followed by twenty zeros) </span>
