For Americans, in particular, this is the trickiest of the lot. Understanding kilometres and litres when all you’ve ever known is miles and gallons. To convert from the first unit shown to the second (e.g. miles to kilometres) multiply by the factor.
To convert from the second unit shown to the first (e.g. kilometres to miles) divide by the factor. So, if you wanted to know how many kilometres 150 miles was you would go 150 x 1.609 = 241 kilometres. Or if you are looking at a car with 56,000 kilometres on the clock and you want to know what that is in miles, you’d go 56,000 ÷ 1.609 = 34,800 miles. There. Easy!