Answer:
59,425 sq mi
Explanation:
When you want to round to the units place, you look at the digit in the number that is in the place to the right of that: the tenths place. Here, that digit is 7, which is more than 4. Because that digit is more than 4, 1 is added to the units place and all the digits to the right of that are dropped.
This gives you 59,424 +1 = 59,425.
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If the tenths digit were 4 or less, no change would be made to values in the units place or to the left of that. The tenths digit and digits to the right would be dropped.
... 59,424.3 ⇒ 59,424 . . . . . for example