Question: How can you rapidly calculate a 20 percent tip?
Options:
Take the total of the bill and move the decimal point one place to the left, double that number and that is 20 percent.
Take the total of the bill and move the decimal point one place to the right, double that number and that is 20 percent.
Answer: Take the total of the bill and move the decimal point one place to the left, double that number and that is 20 percent.