The choices are:
A. Use a system where you measure in fractions, then convert those fractions to decimal numbers in order to use a calculator, then convert the decimal answer back into a fraction. Your basic unit of measure is grouped in such a way that it's divisible by 2, 4ths, 8ths, 16ths, and 32nds or is multiplied by 12.
B. Use a system where you measure in decimals, use no conversion to plug those numbers into a calculator and no conversion of the answer as it's already in decimals. Your basic unit of measure is divisible or multiplied by 10, allowing one to slide the decimal as needed usually sans calculator.
