I tried to parse columns to the Math node and use the variables to perform calculation on the columns. I use a column list loop start, but do not see the currentColumnName variable. I do see it using the string manipulation node. Any suggestions?
The behavior is correct, since the column name itself is only a string you can manipulate the column name (not the value of the cell) with the String Manipulator but not with the Math Formula node. I guess, you want to iterate a set of numeric columns and do the same transformation on all of them, you are required to unify the real column, for example with the Column Rename (Regex) to 'default' and do the same renaming after the Math node again.