Extract Data from Atrribute Table of Shape File to do further Calculations

Discussion created by patflo on Dec 20, 2011
Latest reply on Jan 18, 2012 by patflo
Hello im a beginner of Arcgisand i have following problem

I have a shapefile where i need to some calculations. In the shapefile there are attributes (Area in m², Irradiance in W/m² and temperature in °C???) and I have to do a multiplication. I can do It manual by adding a new field and type in the expression :  Power=Area*Irradiance.
But I need to do this for a lot of entrys and so I want to make a process in the model builder.  How can I extract the data in the attribute table to do the calculations and add a field at the end of the attribute table with the calculated power?

thanks for your help in advance