Answer
Six hundred seventy-eight
Work Step by Step
To write 678 in words you write out each number in its place followed by its period name. The 6 is in the hundreds place in the ones period, so it would be written six hundred then the 7 as seventy- and then the 8 as eight like the number would be spoken. The name for tens and ones place value in the ones period is not added after the number.