How do I ROUND() round off decimals of a column dataset?

[Guest]

After importing data with four decimals into my Excel worksheet, I want to
round off all data to one decimal. It is rather cumbersome to round each
datapoint one by one. Is there a quicker way?

 

[Max]

Try on a spare copy

Assuming your data is in col A, A1 down

Put in B1: =ROUND(A1,1)
Copy down

Select col B

Do a copy > paste special > values > ok
over col A (overwrite col A)

Delete col B