Worksheet Grade 7 Careers & CTE

Marisbrook's Showerhead Rebate: A Conservation Career Worksheet

A grade 7 worksheet putting students in a water conservation coordinator's seat, using flow rates, percent change, and unit rates from a fictional rebate program.

Grade: Grade 7
Subject: Careers & CTE
Material: Worksheet
Time: 35 min
Prep: No prep
Materials: None

Standards

7.RP.A.3 Common Core Math

Use proportional relationships to solve multistep ratio and percent problems. Examples: simple interest, tax, markups and markdowns, gratuities and commissions, fees, percent increase and decrease, percent error.

How this material aligns: Items 3 and 7 require a percent-decrease calculation on shower water use and a percent-increase calculation on rebate applications.

All materials for 7.RP.A.3 →

7.RP.A.2 Common Core Math

Recognize and represent proportional relationships between quantities, including identifying the constant of proportionality and representing proportional relationships by equations.

How this material aligns: Item 8 requires students to find the constant rate of four homes per hour before scaling it to a full day, and items 1 and 2 apply a stated gallons-per-minute rate the same way.

All materials for 7.RP.A.2 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-07-23.

Objectives

Students will compute water use from a flow rate and a length of time.
Students will find percent decrease and percent increase in a conservation program's records.
Students will explain why a utility measures a program in gallons saved.

Vocabulary

Flow rate: Flow rate measures how much water moves past a point in a certain amount of time, like gallons per minute through a garden hose. Bigger pipes and stronger pushes give bigger flow rates.
WaterSense: An EPA label on toilets, showerheads, faucets, and irrigation controllers that meet water-saving standards. It works like the ENERGY STAR label, but for water.

Also: rebate, gallons per minute, conservation

Teacher overview

A water conservation program coordinator runs the projects a utility uses to lower demand, such as rebates, leak repair help, and school programs. The job is part public speaking and part accounting, because every program has to report the water it actually saved. Coordinators reach the role by more than one route, including promotion from a utility's meter or customer service staff, a two-year environmental technology degree, and a four-year degree in environmental studies or public communication. This worksheet places students in that seat at a utility in the fictional town of Marisbrook, where Nia Adeyemi runs a showerhead rebate. Students commonly compute percent change against the ending value instead of the starting value, so items 3 and 7 are written to expose that error before the two reasoning items at the end.

Marisbrook's Showerhead Rebate: A Conservation Career Worksheet — Grade 7 Careers & CTE

Name: ____________________________ Date: ______________

Student Worksheet

Nia Adeyemi is the conservation program coordinator for the town of Marisbrook. Suppose she is reporting on the town's showerhead rebate. Use the numbers given in each item.

A standard showerhead flows at 2.5 gallons per minute. How many gallons does an 8-minute shower use with that showerhead?
A WaterSense showerhead flows at 2.0 gallons per minute. How many gallons does the same 8-minute shower use with that showerhead?
An 8-minute shower uses 20 gallons with a standard showerhead and 16 gallons with a WaterSense showerhead. What percent less water does the WaterSense showerhead use?
Suppose one home saves 4 gallons per shower and takes 2 showers each day. How many gallons does that home save in one day?
Marisbrook gave a showerhead to 450 homes. If each home saves 8 gallons a day, how many gallons do all 450 homes save in one day?
EPA reports that household leaks waste about 9,400 gallons a year in an average home. Nia helped 30 homes find and fix leaks. How many gallons a year is that in total?
The rebate program received 320 applications one year and 400 applications the next year. What was the percent increase?
Nia visits 12 homes in 3 hours. At that same rate, how many homes can she visit in an 8-hour day?
Explain why Nia reports gallons saved instead of the number of showerheads she handed out.
The average US household uses about 300 gallons of water a day. Explain why a saving of 8 gallons a day in one home still matters to a utility that serves thousands of homes.

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Answer Key

Answer: 20 gallons. Multiply 2.5 gallons per minute by 8 minutes.
Answer: 16 gallons. Multiply 2.0 gallons per minute by 8 minutes.
Answer: 20 percent. The drop is 20 minus 16, which is 4. Divide 4 by the starting value of 20 to get 0.2, then multiply by 100. A student who divides by 16 has used the ending value.
Answer: 8 gallons. Multiply 4 gallons per shower by 2 showers per day.
Answer: 3,600 gallons. Multiply 8 gallons per home by 450 homes.
Answer: 282,000 gallons. Multiply 9,400 gallons per home by 30 homes.
Answer: 25 percent. The rise is 400 minus 320, which is 80. Divide 80 by the starting value of 320 to get 0.25, then multiply by 100.
Answer: 32 homes. Divide 12 homes by 3 hours to get 4 homes per hour, then multiply by 8 hours.
Answer: Accept any reasoned response. Sample response: a showerhead that sits in a closet saves nothing, so counting devices can make a program look better than it is, while gallons saved measures the result the utility actually wants.
Answer: Accept any reasoned response. Sample response: one home's saving is small next to 300 gallons a day, but the same saving repeated across thousands of homes adds up to a large amount, and it costs far less than building new supply.

Differentiation

Support

Provide items 3 and 7 with the subtraction already completed so students begin at the division step, and print a reminder that the starting value goes in the denominator. Allow a calculator throughout. For item 8, give the intermediate rate of 4 homes per hour and ask only for the daily total.

Extension

Ask students to build the one-page summary Nia would hand her manager. It should report the daily savings from item 5, the yearly leak savings from item 6, and one sentence naming a number the report cannot prove. Students must label every figure with the item it came from.

ELL supports

Pre-teach "flow rate," "rebate," and "savings" with a labeled drawing of a showerhead and a bucket filling for one minute. Provide sentence frames for items 9 and 10, such as "Nia counts ____ because ____." Allow short phrases rather than full sentences on those two items.

Extensions

Have students time a faucet or a showerhead at home or at school by filling a marked container for one minute, then use that measured flow rate to estimate their own household's shower use for a week. Students compare their measured rate with the two rates in items 1 and 2 and write one sentence about which fixture in their home they would replace first.