scale/resistance voltage for pin (0)

I am wanting to get reading from a temp sending unit, voltage is scaled 0-5v and resistance is from 13.5k to 20ohms.
I know pin0 can read 1024 different levels, I only want to break this into 4 or 5 sections , example only know if it is >2500 , <2500 but > 450, etc. or could I do it a different way and measure the voltage? >1v but < 3v?
I am using an arduino mega 2560 and pololu vnh5019. I am trying to use these readings to drive an actuator to 4 or 5 different positions depending upon temp.
Could anyone help me with this? I hope I explained it correctly.

The value returned by analogRead() is indeed in the range of 0 to 1023. You can use the map() function to map that to a different range. Or, a series of if/else if/else statements can select non-uniform ranges, if that works better.

Thank you.