Round \[13.681\] to one decimal place.

Hint:While rounding a number to one decimal place we should consider the number in the second decimal place and analyze its value. There are different processes performed depending on the nature of the number present in the second decimal place i.e. considering if it greater than or lesser than the number 5.
So based on the above statement we can perform the same steps for the number given and then round it to one decimal place.

Complete step by step solution:
Given
$13.681...................\left( i \right)$
Now from (i) we can see that in the given number we have 6 in first decimal place and 8 in the second
decimal place.
Such that while rounding a number to one decimal place we have to consider the number present in the second decimal place and analyze its value:
a) If the number in the second decimal place is greater than 5 then it’s rounded up.
b) If the number in the second decimal place is lesser than 5 then it’s rounded down.
So here in the first decimal place we have 6 which can be rounded to either 7 or 5 depending on the number present in the second decimal place.
Here at the second decimal place we have 8 which is greater than 5 so the number $13.681$ is rounded up such that the number 6 is rounded up to the next greatest number 7.
Therefore on rounding $13.681$ we get$13.7$.

Note: On solving questions similar to the above one we should always take care about the two rules mentioned above such that it would be easier to execute the simplification process. Rounding of a number simply means the process of replacing it with another number such that it’s nearly equal and can be represented in a much easier way.