Does it have a digital temperature display?

yes
they are using a oven thermetor to keep track of what the tempature is.

No, if your oven has a digital temp control, it's a little more complicated to calibrate the temp. If it's manual (older models) then it's slightly easier.

so what do you think the problem is?
thanks
Ron

any ideas?

when we had issues with our stove, we were able troubleshoot it through this site - http://www.repairclinic.com/Range-Stove-Oven-Troubleshooting?red=#itbakespoorly_electric That should be able to give you a rough idea on how to calibrate the temperature gauge so that it works more accurately.