A family of four goes out to dinner. The total price for their food and drink purchases is $54.88. The sales tax is 5%. How will the waitress determine the amount of tax to add to the bill?

Multiple the total by .10 or 10% (move the decimal place one to the left).  Doing that gives 10% of the total or $5.48.  To get 5%, divide that number in half for $2.74.  

Step-by-step explanation:

This is the same for determining a tip of 20%.  Move the decimal one to the left and double that number.  For 15%, move the decimal place one to the left.  There's 10%, half that, and add the two numbers together for 15%.

the answer is 0.071

good luck! : d