The numbers given are:
98 749 000 = 9.8749000 x 10^7
990.000 = 9.90 x 10^2
89 987 000 = 8.9987000 x 10^7
In scientific notation, the number with the smallest exponent is the smallest number. So, the number 990.000 (expressed as 9.90 x 10^2 in scientific notation) is the smallest among the three.