Question

What is the total cost of two dozen erasers that are priced at 50 cent each if 8%sales tax is added.

Answer 1

Let's translate this question into a formula:

Total cost = (unit price of the eraser) (number of erasers purchased) 

Final total cost = (Total cost) * 1.08 = ?

Why?  The Final Total Cost = Cost of the erasers   +   (Cost of the erasers)(sales tax rate)

Final total cost = 1.08 (Total Cost)
Final total cost = 1.08 ($0.50)(24)    (since 1 dozen = 12, and 2 dozen = 24)