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Lesson plan Grade 4 Health & Consumer Science

Shower Swap at the Quimby House: Counting the Gallons Saved

A grade 4 lesson where the fictional Quimby family installs a WaterSense showerhead and students use whole-number math to find the gallons saved each week.

Objectives

  1. Students will calculate how many gallons a family saves per shower and per week after switching showerheads.
  2. Students will use multiplication and division to compare shower water use before and after the swap.

Vocabulary

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: showerhead, conserve

Teacher overview

This consumer science lesson follows the fictional Quimby family as they replace an older showerhead with a WaterSense-labeled model. A standard showerhead flows at 2.5 gallons per minute, while WaterSense-labeled models use 2.0 gallons per minute or less, which means a ten-minute shower drops from 25 gallons to 20. A common misconception among fourth graders is that a difference too small to notice during one shower cannot amount to much water; the weekly totals in the handout are designed to correct that belief with the students' own multiplication.

Procedure

Hook (5 min): Ask students to guess how many gallons of water a ten-minute shower uses. Record guesses on chart paper without comment. Guesses often land far from the figure the class will compute, which gives the lesson a question worth settling.

Direct instruction (10 min): Present the two flow rates: a standard showerhead flows at 2.5 gallons per minute, and a WaterSense-labeled model uses 2.0 gallons per minute or less. Model on chart paper how a ten-minute shower with the standard head uses 25 gallons, adding the flow rate minute by minute so students see where the total comes from. Introduce the scenario: imagine the Quimby family, whose old showerhead used 25 gallons per ten-minute shower, has installed a new one that uses 20 gallons for the same shower.

Guided practice (12 min): In pairs, students find the savings for one shower (25 - 20 = 5 gallons) and then the family's shower use for one day if four people each shower once. Circulate and ask pairs to explain which operation they chose and why. Formative check: ask pairs to hold up their one-day total on a whiteboard; if fewer than three-quarters of pairs show 80 gallons, re-model the multiplication before moving on.

Independent practice (13 min): Students complete handout questions 1 through 4 on their own. Early finishers can check their work by solving question 3 a second way, multiplying the per-shower savings by the total number of weekly showers.

Closure and exit ticket (5 min): Question 5 on the handout is the exit ticket. Collect it and scan for correct multiplication before dismissal.

Shower Swap at the Quimby House: Counting the Gallons Saved — Grade 4 Health & Consumer Science
Name: ____________________________ Date: ______________

Student Handout

Imagine the Quimby family has just installed a new WaterSense showerhead. Answer each question. Show your work.

  1. The Quimbys' old showerhead used 25 gallons of water during one ten-minute shower. The new showerhead uses 20 gallons for the same shower. How many gallons does the new showerhead save in one shower?
  2. Four family members each take one ten-minute shower every day. Each shower with the new showerhead uses 20 gallons. How many gallons does the family use for showers in one day?
  3. The new showerhead saves 5 gallons in every shower. The family takes 4 showers each day. How many gallons does the family save in one week of 7 days?
  4. The family wants to save 100 gallons in all. Each shower saves 5 gallons. How many showers will that take?
  5. Exit ticket: A neighbor's new showerhead saves 4 gallons in each shower. After 10 showers, how many gallons has the neighbor saved?

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

Answer Key
  1. Answer: 5 gallons.
    The old showerhead used 25 gallons and the new one uses 20 gallons, and 25 - 20 = 5.
  2. Answer: 80 gallons.
    Four showers at 20 gallons each is 4 x 20 = 80 gallons in one day.
  3. Answer: 140 gallons.
    Savings each day are 5 x 4 = 20 gallons, and 20 x 7 = 140 gallons in a week. Students may also compute 4 x 7 = 28 showers, then 28 x 5 = 140.
  4. Answer: 20 showers.
    100 ÷ 5 = 20, so the family reaches 100 gallons of savings after 20 showers.
  5. Answer: 40 gallons.
    4 gallons per shower times 10 showers is 4 x 10 = 40 gallons.

Differentiation

Support

Provide a partially completed table with columns for showers, gallons used, and gallons saved, with the first row filled in as a model. Allow skip-counting by fives on a number line for questions 3 and 4 instead of formal multiplication and division notation.

Extension

Ask students to figure out how many gallons the family would save in a 30-day month at 20 gallons of savings per day, and then to write one sentence about whether the answer surprised them and why.

ELL supports

Pre-teach "showerhead," "save," and "per shower" with a labeled diagram of a shower. Provide sentence frames for explaining work: "The family saves ___ gallons because ___ x ___ = ___." Pair students so each pair shares a strong reader for the word problems.

Extensions

With a parent or guardian, students time one real shower to the nearest minute, then use the class rates to estimate the gallons it used and compare that estimate with the Quimby scenario. Results will differ from household to household, which sets up a short class discussion about why real families' water use varies.