91, 937 rounded off to the nearest tens is 91, 940.
First, we need to spot the digit in the tens place, which is 3, and then we're going to check the digit in its right, that is 7, then apply the rules in rounding off.
0 - 4 = stays the same 5 - 9 = +1
Since the digit on its right is 7, we're going to add one on that digit so 3 will going to be 4.
What will happen to 7?
·It will simply become 0. Always remember that the digits on its right will become 0 while the digits on its left will stay the same.