Yeah, the more I look at their rounding the less sense it makes. OK, 39°50′N goes to 39.8333333. 50/60 is approximately 0.8333. Fine. But, 98°35′W should be -9

Yeah, the more I look at their rounding the less sense it makes. OK, 39°50′N goes to 39.8333333. 50/60 is approximately 0.8333. Fine. But, 98°35′W should be -98.5833333, by the same rule they apparently just used, not 98.585522. And I certainly don't see how 39.8333333 rounds to 38.0000 instead of 40.0000, or how -98.5833333 rounds to -97.0000 instead of -99.00000. It's like they rounded down and then subtracted 1.