#### Answer

Tens: 20,070; Hundreds: 20,100; Thousands: 20,000

#### Work Step by Step

To round to the nearest ten:
1. See digit to the right of the tens place: 5
2. Round up by changing 6 to 7, and change digits to the right to 0.
3. We get 20,070 as the new rounded number.
To round to the nearest hundred:
1. See digit to the right of the hundreds place: 6
2. Round up by changing 0 to 1, and change digits to the right to 0.
3. We get 20,100 as the new rounded number.
To round to the nearest thousand:
1. See digit to the right of the thousands place: 0
2. Round down by leaving thousands place unchanged and change digits to the right to 0.
3. We get 20,000 as the new rounded number.