I think the answer is correct becuase, If we taken all the numbers and put them on a number line they would all be under one. But when we look at the number line we would see that .987 is the closest because it is almost a whole number. And even if we did it without the number line what ever number we see that has the greatest digit and its in the negatives thats the closest to one. (I hope what I said makes sense!)
