// compute mantissa if number were written in scientific notatation
int exponent = (int)(math.floor( Math.log10( value ))) + 1;
double mantissa = value * Math.pow( 10.0, -exponent );
// e.g. 12345.0 ->  0.12345E06 -> exponent 6, mantissa  0.123454.
// regular (int) rounds toward 0.