New York 7 - 2020 Edition
6.06 Sales tax and tip
Lesson

Two ways that percentages are commonly used in the U.S. are when calculating the amount of sales tax we will need to pay for purchasing an item and when calculating the proper tip to leave the waitstaff at a restaurant.  Interestingly, we will find that in different parts of the United States the amount of tax that we will pay for the purchase of goods or services can vary.  In addition, while tipping for good service is a common practice in the U.S., there are other countries that do not engage in the practice of tipping at all.

### Tips

This image below, from mint.com, displays the tipping customs of many countries around the world.  You can see that tips vary from $0$0 to $20%$20%

Tipping is an amount of money left for the staff, in addition to paying the bill, as a sign that we appreciate good service. Tips are common in the service industry, but in other sectors like government receiving a tip can be considered illegal.  So, it is important to know the customary amount to tip for different services and who we should not offer a tip to.

#### Worked examples

##### Question 1

David is paying for a meal with lots of friends. They received great service, so he is giving a $20%$20% tip. The meal came to $\$182.30$$182.30. How much will he leave as a tip? Think: I need to work out 20%20% of the total meal charge. 20%20% as a fraction is \frac{20}{100}20100. Do: 20%20% of \182.30$$182.30

 $20%$20% of $\$182.30$$182.30 == \frac{20}{100}\times\182.3020100​×182.30 20%20% is \frac{20}{100}20100​ and of in mathematics means multiplication. == \frac{20\times182.30}{100}20×182.30100​ == \36.46$$36.46

### Outcomes

#### NY-7.RP.3

Use proportional relationships to solve multistep ratio and percent problems.