How to calculate sum of two columns?

I have a table with a few colums: eg. date, silo1, silo2, total

How do i calculate the total or sum from the colums "silo1" and "silo" ?

eg: total = silo1 + silo2

Primary i want a gauge to show the latest total value.(sum of the two silos)

I am not an experienced developer, but i hope someone can help me her.

Regards dkhp

Please check this video for more info:

Thanks for that link, that helped me.
Do i need to use a DataList to use the Gauge element to show the latest value in gauge? or is there a better way?

You can use the Gauge component separately.