Doing calculations with an exact number type such as [big] rationals, and then explicitly converting to floating point or rounding/truncating digits of precisio

Doing calculations with an exact number type such as [big] rationals, and then explicitly converting to floating point or rounding/truncating digits of precision as needed, is a pretty good middle ground for many applications. 109/100 − 109375/100000 = 109/100 − 35/32 = −3/800 = −3.75ᴇ−3.