Im's So confused about stoichiometry.

My question is this

use stoichiometric calculations to predict the mass of solid product fromed in the reaction from the knwon mass of sodium hydrogen carbonate used.

Balenced equation:

4NaHCO3 = 4Na + 2H2O + 4CO + 3O2

Your question is not entirely clear and you don't provide any numbers. Are you using NaHCO3 in a reaction or are you decomposing NaHCO3?

The general way of solving these equations is as follows:
1. Write the balanced chemical equation.
2. Convert what you are given into mols. Usually the problem gives grams. If that is the case then # mols = grams/molar mass.
3. Now use the coefficients in the balance equation to convert mols of what you were given into mols of what you want.
4. Then convert mols of what you want to grams remembering that grams = mols x molar mass.

If you will provide numbers for your question and some indication of the reaction (what you have written probably is incorrect unless you are doing something which which I am unfamiliar) perhaps I can guide you through the problem. Stoichiometry really is a simple process. There are only 4-5 steps and a regular process. Once you do that the problems are solved.