I'll try to help you round these numbers
37 rounded to Tens will be 40
because 7 is bigger than 3 so the 7 will change the 3 to a 4 and the 7 will be a 0.
29 rounded to Tens will be 30
because the 9 is bigger than 2 so it will change the 2 to a 3 and the 9 will be a 0. Just like 37 rounded into a 40.
669 rounded to Hundreds will be 700
Its 700 because the 9 is bigger and it will change the 6 beside it to a 10 which means that the 9 will be a 0. The 6 that turned to a 10 will turned will be a 0 because your carry the 1 to the other 6 which would turn to a 7 and the two numbers behind 7 will be 0's which makes that be 700.
9,492 rounded to Thousands will be 9,000
Ok this is 9,000 because the 4 is smaller than 9 which the 9 will become the bigger person and turn all the little numbers thats behind it to 0's and even that 9 between the 4 and the 2. So thats why its 9,000.
Hope this helps!