When you go out to eat with family or friends, how much do you generally tip a restaurant server? Although etiquette expert Diane Gottsman says an 18% to 20% gratuity is standard these days, there ...

Moving the decimal, double the number: With this method, find the post-tax total on the bill, move the decimal one place to the left and double the number. For the $38.65 bill shown above, you get ...