The answer depends on the degree to which you are estimating. To the nearest thousand it is 1 thousand; to the nearest hundred, it is 600 and so on.
79.75
What does 638 mean
638
638 + 577 = 1215
253 + 638 = 891
507-638 = -131
638 x 34 = 21,692
638 x 2.9 = 1850.2
The factors of 638 are 1, 2, 11, 22, 29, 58, 319, and 638. The prime factorization of 638 is 2 x 11 x 29.
638 kilograms = 22,504.8 ounces
1.9875
638 meters = 2,093.175 feet