Percentages in the Real World
Taxes, tips, mark-ups, discounts, and commissions.
Tax is extra money added on to a bill to pay to the city, state, or federal treasury.
Tips are money you give to waiters/waitress's for services at restaurants.
Mark-ups is when you buy something at its own price, then sell it for a bigger price
Discounts is when you get a small price off a bill, usually with coupons or sales.
Commission is where people who try to sell stuff get a part of a sale.