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Tip Jar (Updated!)

What’s the fairest way to tip at a restaurant?

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Tip Jar (Updated!)

What’s the fairest way to tip at a restaurant?

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Tip Jar - Student Handout.pdf
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Tip Jar - Teacher Guide.pdf
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2023-2024 Versions

In the fall of 2024, Citizen Math released updated versions of every lesson in our library, plus a few new ones! We know you may have already prepped an earlier version or planned a repeat of last year, so we're continuing to make these earlier versions available through Thursday December 5, 2024.

You can find the new lessons through the regular search, and we hope you love them as much as we do. You can read more about these updates in Our Community.

What’s the fairest way to tip at a restaurant? When you go out to eat in the United States, it’s customary to leave a tip as a percent of the total bill. When we do this, though, we don’t compensate servers for how hard they work but rather for how expensive the restaurant is.

Students use percents to calculate tips for different restaurant bills and debate the best ways to compensate waiters and waitresses.

REAL WORLD TAKEAWAYS

  • In the United States, it’s convention to tip as a percent of the total bill at restaurants.
  • A tip can be quickly approximated on the fly by reasoning proportionally from 10%. A 20% tip is double 10%; a 15% tip can be thought of as 10% plus half of 10%.
  • Tipping as a percent ties server compensation to the cost of food rather than how much work it takes to serve it.

MATH OBJECTIVES

  • Reason proportionally to solve real-world problems
  • Calculate percent of a whole, and understand a percent as a rate out of 100
Great anytime, including at the beginning of a unit before students have any formal introduction to the topic.
Grade 6
Percents
Grade 6
Percents
Content Standards 6.RP.3 Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams, double number line diagrams, or equations. (a) Make tables of equivalent ratios relating quantities with whole- number measurements, find missing values in the tables, and plot the pairs of values on the coordinate plane. Use tables to compare ratios. (b) Solve unit rate problems including those involving unit pricing and constant speed. For example, if it took 7 hours to mow 4 lawns, then at that rate, how many lawns could be mowed in 35 hours? At what rate were lawns being mowed? (c) Find a percent of a quantity as a rate per 100 (e.g., 30% of a quantity means 30/100 times the quantity); solve problems involving finding the whole, given a part and the percent. (d) Use ratio reasoning to convert measurement units; manipulate and transform units appropriately when multiplying or dividing quantities.
Mathematical Practices MP.3 Construct viable arguments and critique the reasoning of others. MP.7 Look for and make use of structure. MP.8 Look for and express regularity in repeated reasoning.

Other Grade 6 Lessons

Jenius! (Updated)

How does what we see affect what we feel?

Grade 6
Ratios & Unit Rates
Great anytime, including at the beginning of a unit before students have any formal introduction to the topic.

New-Tritional Info (Updated!)

Should restaurants rewrite menus in terms of exercise?

Grade 6
Equations & Expressions
Great anytime, including at the beginning of a unit before students have any formal introduction to the topic.

AlgoRhythm

What are the consequences of personalization algorithms?

Grade 6
Ratios & Unit Rates
Great anytime, including at the beginning of a unit before students have any formal introduction to the topic.

Downside Up (Updated!)

Is there an upside to having a bad day?

Grade 6
Positive & Negative Integers
Great anytime, including at the beginning of a unit before students have any formal introduction to the topic.

1600 Pennsylvania (Updated!)

How big is the White House?

Grade 6
Area/SA/Volume
Appropriate most times as students are developing conceptual understanding.

Jenius! (Updated)

How does what we see affect what we feel?

Grade 6
Ratios & Unit Rates
Great anytime, including at the beginning of a unit before students have any formal introduction to the topic.

New-Tritional Info (Updated!)

Should restaurants rewrite menus in terms of exercise?

Grade 6
Equations & Expressions
Great anytime, including at the beginning of a unit before students have any formal introduction to the topic.

AlgoRhythm

What are the consequences of personalization algorithms?

Grade 6
Ratios & Unit Rates
Great anytime, including at the beginning of a unit before students have any formal introduction to the topic.

Downside Up (Updated!)

Is there an upside to having a bad day?

Grade 6
Positive & Negative Integers
Great anytime, including at the beginning of a unit before students have any formal introduction to the topic.

1600 Pennsylvania (Updated!)

How big is the White House?

Grade 6
Area/SA/Volume
Appropriate most times as students are developing conceptual understanding.