354
The smallest number that rounds to 8000 is 7500. When rounding to the nearest thousand, numbers that are 500 or greater get rounded up. In this case, 7500 is the smallest number that, when rounded to the nearest thousand, becomes 8000.
7200
3,500,000 rounds up. 3,499,999 rounds down.
3,500,000 rounds up. 3,499,999 rounds down.
199
The mystery number is 155. When rounded to the nearest hundred, it rounds to 200. The sum of its digits is 1+5+5=11 which is greater than 10, so we must adjust the digit in the hundreds place. When rounded to the nearest ten, 155 rounds to 160, which has digits summing up to 1+6+0=7.
3,500,000 rounds up. 3,499,999 rounds down.
8600
800
300
70
Rounded to the nearest 10: 50 004 Rounded to the nearest 100: 50 049 Rounded to the nearest 1000: 50 499 Rounded to the nearest 10,000: 54 999