Relative atomic mass number/mass numberWatch
The atomic/molecular molar mass is just the mass of 1 mole of an atom/molecule. It has units of mass, so grams usually.
Of course they have the same numerical value, just the units that are different.
Edit: Just realised, you said something different again! The mass number of an atom is the number of protons + the number of neutrons. It is again not a mass, as it's just the number of particles in the nucleus. I'd think of that, and the relative atomic mass ass the same thing, especially if you're doing GCSEs! They're only different because a neutron has a ever so slightly greater mass, but you can definitely ignore this unless you were doing some very accurate experiment!
Scientists get very anal about terminology like this; the words have very precise meanings even though in many, many cases you'd be able to interchange the terms.
As mentioned above it has no units, being a relative measurement.
The mass number is just the sum of the protons and the neutrons in one specific isotope of an element.