Floating-PointNumbers I
see Scientific Notation p.5 in the Algonquin CST8110 Blue Book
Floating-point numbers are stored as separate mantissa (fraction) and exponent
Limits on the size of the mantissa and exponent limit the precision (accuracy) and range of floating-point numbers
precision: # bits used in mantissa
1.234567 E1
1.234567890123456789 E1
range: # bits used in exponent