Many are confused with what to use, either plural or singular when it comes to time, distance and amount. Fortunately, there is a small rule that caters for measurements of distance, time, and amount when it comes to subject - verb agreement which takes the sum as a singular amount, and thus they take singular forms of their verbs.
WRONG $500,000 worth of Bitcon have been stolen from my account.”
RIGHT “$500,000 worth of Bitcon has been stolen from my account.” (correct)
WRONG “800 kilometres from here are too much to travel in that car.”
RIGHT “ 800 kilometres from here is too much in that car.”
WRONG “Three hours of sleep are very small. ”
RIGHT Three hours of sleep is very small. ”