How to do this chemistry problem

One type of feldspar has the formula CaAl2Si2O8. How many grams of aluminum can be obtained from 1276kg of feldspar?
Can you explain how to get the answer?

Add up the "molar weight" of the ore and divide it into two times the atomic weight of aluminum. That is the fraction of Al in feldspar. Multiply that fraction by the mass of feldspar given and you'll have the mass of aluminum possible to be obtained.

Obtain the mass of each component from the Periodic table and add them together.
Then take the mass of each component and divide it by the combined total and mutiply this answer by the mass of feldspar to obtain the Aluminium obtained

Mol.mass of CaAl2Si2O8 = Ca:40 + Al2: 54 + Si2: 56 + (O 8: 128) = 278.

Of this, Al = (54 / 278) = 0.1942 x 1276kg = 248kg of Aluminium.

Find the molecular .= 278 9 2 x Al = 54g
grams of Al = 54 / 278.9 x 1276 kg = 247Kg