Rounding off to the nearest 10

Rounding off is a method of approximating a number to the nearest value. In this case, we are asked to round off the number 20518 to the nearest 10. Here's how to do it:

1. Identify the digit in the ones place
The ones place is the rightmost digit in the number. In this case, the ones place digit is 8.

2. Determine if the ones place digit is 5 or greater
If the ones place digit is 5 or greater, we round up. Otherwise, we round down. In this case, the ones place digit is 8, which is greater than or equal to 5.

3. Increase the digit in the tens place by 1
To round up, we need to increase the digit in the tens place by 1. In this case, the digit in the tens place is 1. Adding 1 to it gives us 2.

4. Set all digits to the right of the tens place to 0
To round off to the nearest 10, we need to set all digits to the right of the tens place to 0. In this case, the digits to the right of the tens place are 5 and 8. Setting them to 0 gives us 20.

Therefore, rounding off 20518 to the nearest 10 gives us 20520.