A tip is a small amount of money given to someone for performing a service. It’s also known as a gratuity. Some people think it’s rude to leave pennies on the restaurant table. Some servers, however, like the small change so they can make change for the next guest right from their apron pockets.
- To calculate 5%, 10%, and 15%, and 20% percent of a given quantity.
No one likes a math lecture, so the best way to teach is by letting your kids do. Kids respond well to getting a chance to try to figure out something for themselves. Even before you begin eating, your children can practice calculating the tip. Tipping is based on the restaurant bill before the tax is added. A customary tip should be no less than 15%.
To calculate 5%, move the decimal one place to the left and divide the number by two. For example, a $15.38 tab would become $1.538. Divide that amount in half to get 5% ( .77).
To figure 10%, move the decimal one place to the left. For example, a $15.38 tab would become $1.538 or, rounded up, $1.54.
To calculate 15%, figure out 10% and add half of that amount (which is 5%) to it, e.g., $1.54 (10%) + .77 (5%) = $2.31 (15%).
To calculate 20%, move the decimal point one place to the left to get 10% and then double it e.g., $15.38 would become $1.53 (round it down to $1.50) and then double it to come up with $3.00.
As they grow, show children how math is part of daily life, as you make change, or measure ingredients, or decide how soon to leave for a destination 10 miles away, says Mann Koepke, of NIH’s National Institute of Child Health and Human Development.
Marilyn Buehrer is a Middle School English Teacher and a specialist in Home Schooling.