2. hddtemp (will ask if you want to run at startup) Yes
Right click panel --> click Add to panel, Scroll down and click on Hardware Sensors Monitor
A single sensor should appear that probably reads 40 C
In a terminal type sudo sensors-detect
Answer YES to ALL questions
Reboot --> Enter BIOS --> Find your hardware monitor stats, take note of the temps as they will guide you in determining which temp is what in the sensors applet display.
Right click on sensor icon, click Preferences, click on an item, click properties, change Sensor Value Multiplier so temp changes to what what you saw in BIOS.
Change the label from Temp 3 to CPU or whatever matches your system.