40000 mm to km conversion result above is displayed in three different forms: as a decimal (which could be rounded), in scientific notation (scientific form, standard index form or standard form in the United Kingdom) and as a fraction (exact result). Every display form has its own advantages and in different situations particular form is more convenient than another. For example usage of scientific notation when working with big numbers is recommended due to easier reading and comprehension. Usage of fractions is recommended when more precision is needed.
If we want to calculate how many Kilometers are 40000 Millimeters we have to multiply 40000 by 1 and divide the product by 1000000. So for 40000 we have: (40000 × 1) ÷ 1000000 = 40000 ÷ 1000000 = 0.04 Kilometers
So finally 40000 mm = 0.04 km