We have to round the value of 0.1561 to the nearest tenth.
The number after decimal is the number at tenth place. Consider the number to the right of the tenths place and use the number to determine if you will round up or stay the same. Notice that the number to the right of tenth place is more than or equal to 5 or less than 5. If that number is greater than or equal to 5, then the number will round up but if that number is less than 5, then the number will not round up. It will remain same.
Let us consider the given number 0.1561
The number at tenths place is 1
The number after the tenths place is 5 (which is either greater than or equal to 5)
So, the number will round up to 0.2