List.Sum Error in Power Query

[Anonymous]

Hi Experts

I am tryting to sum the following values in the column as shown into a new column - cannot see my mistake

My Custom column M Script = List.Sum({[TOTALCOST_]}) - gives me the same answer as the image shown

[Anonymous]

thanks

[Ahmedx · Accepted solution]

everything is correct, if you want to sum up the entire column, then you need to add the name of the last step with the name of the column