A 5-kilometre route has 0.4 kilometres left. How far has been completed?

Բացատրություն

Write the whole number as 5.0, then subtract: 5.0 - 0.4 = 4.6 kilometres completed. Subtracting the visible digits as 5 - 4 = 1 ignores that 0.4 is four tenths rather than four whole units.