Question

When you describe a quantity with more than one familiar unit (such as kilometers or millimeters for a length), how can you decide which is a more appropriate unit to use? while it is not incorrect to use the less appropriate unit, why do you want to avoid using it anyway?

Answer 1

When describing a quantity with a known appropriate unit, you simply have to use the correct unit after stating the quantity. Yes, it is correct that it might be okay to express the quantity in the less appropriate unit, however, this can cause confusion among the individuals that might refer to or make use of the quantity.