The thousands digit is 7. The digit to the right of that is 6, which is more than 4. That means, the 7 must be increased by 1 (to make it 8) when the number is rounded to thousands.

428,000 is the nearest thousand.

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In a computer, this is often accomplished by adding half a thousand before truncating the number (replacing all of the digits below the thousands digit by 0).

427,685 + 500 = 428,185 ≈ 428,000

428,000 is the nearest thousand.

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In a computer, this is often accomplished by adding half a thousand before truncating the number (replacing all of the digits below the thousands digit by 0).

427,685 + 500 = 428,185 ≈ 428,000