Why answer 10 year old questions?
For the first one; set it for 20,000 ohms and the reading should be between 12 and 18. You will not be able to read less than an ohm on your meter, it is not sensitive enough. Not sure I have ever seen one that sensitive.
For more Try this ohms law calculator app through which you can easily came to know about the calculations of voltage,current and resistance.
Knowing the power, calculate the current flowing through the thermostat - this is the ratio of the power to the voltage of the mains (110V):
For security, we'll count everything on the draft, the formulas are taken from the site of the homework answers and using the calculator, we calculate for a few minutes our resistance (Ohm).
I = P / U, Ampere.
After calculating the current, determine the resistance: The ratio of the voltage (110V) to the current:
R = U / I, Ohm.
Or you can immediately calculate the resistance by the following formula:
R = U² / P, Ohm.