Hello.
The atomic mass of gold is 196.96657u. In order to round to the nearest whole number, we must look one place to the right of that place value. If that number has a value of 5 or higher, we can round up.
For example;
1.54; round to the nearest whole number.
Since the place value to the right (tenths) has a value of 5 or higher, we can round our whole number up to 2.00.
Let's apply this information to our current problem.
196.96657; round to the nearest whole number.
The whole number is "196", so let's take a look at the place value to the right of "6" - it is 9. As it is higher than 5, we can round our whole number up by 1.
Our new number is: 197.
Your answer is: 197.
I hope this helps!