Balance the equation

Question: Reaction of bromine with sodium carbonate in aqueous solution gives sodium bromide and sodium bromate with evolution of carbon dioxide gas. How many numbers of sodium bromide molecule is involved in the following balanced reaction?

Solution: First let us write down the reaction.

 Now the above reaction is not balance because in a balance equation, number of atom of an element remains equal in both sides. So let us balance the given equation:

 

Thus, it is clear that there are 5 sodium bromide molecules involved in the above balance equation.