math + addRow

Using dhtmlxTreeGrid_pro_v16_80512

I have a math column (ron[=c2*c4]) and it show “N,aN” when I use addRow. I call addRow with: c2=10, c4=10 and the math row=’’.

How can I make to show the calculates value?

The NaN value means that some of operand was not a number
Please be sure that there are no surrounding whitespaces around the numeric value.
Beware that column indexes are 0 based and c2 - related to third column