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Classroom activity Grade 4 Health & Consumer Science

Leak Patrol: A Drip-Count Station Rotation at Carrigan School

A grade 4 station rotation where groups turn one-minute drip counts from five fictional school fixtures into hourly totals and rank the worst leak.

Objectives

  1. Students will multiply a one-minute drip count by 60 to find drips in one hour.
  2. Students will rank five leaking fixtures by their hourly drip totals.
  3. Students will explain why a slow drip adds up to a large amount of water over time.

Vocabulary

Key words: leak, drip, fixture, per hour

Teacher overview

This is a five-station rotation for groups of three or four students. Each station is a card standing in for one leaking fixture in a fictional school building, and each card reports how many drips a custodian counted there in one minute. The rotation is built around a single step of arithmetic, because a one-minute count looks small until groups multiply it by 60 to describe the hour, and only then does the ranking of the fixtures show the size of a slow leak. Groups finish by ordering all five fixtures and recommending which one the custodian should repair first.

Activity Directions

  1. Before class, print the five fixture cards described in step 2 and tape one card at each of five spots around the room, far enough apart that groups do not crowd. Print one student handout per student. Post a blank ranking chart on chart paper at the front.
  2. The five cards, all describing the fictional Carrigan School, read as follows: Station 1, the Room 12 sink, 15 drips in one minute; Station 2, the gym hallway fountain, 24 drips in one minute; Station 3, the cafeteria hand sink, 8 drips in one minute; Station 4, the custodian's mop sink, 32 drips in one minute; Station 5, the playground spigot, 45 drips in one minute. The same numbers appear on the student handout, so students never depend on reading a card from across the room.
  3. Open with the rule that runs the whole rotation: a leak is measured for one minute because nobody can stand and count for an hour, and the count is then multiplied by 60 to describe the hour. Model that step with the Room 12 sink at the front of the class, writing 15 x 60 on the board and asking two students to explain the place-value strategy they used.
  4. Form groups of three or four and send one group to each station. Groups work handout item 1 at Station 1, item 2 at Station 2, and so on, so each group solves a different problem at each stop.
  5. Ring the chime every four minutes and rotate groups one station clockwise. After five four-minute stops, about 20 minutes in all, every group has visited every station and completed handout items 1 through 5.
  6. Bring the class together and fill the ranking chart: call for the hourly total from each station, write the five totals on the chart, and have the class order them from smallest to largest. Groups then finish handout items 6 through 10 at their seats.
  7. Debrief for five minutes with two questions. First, ask which fixture wasted the most and whether the hour total changed anyone's first guess about which leak looked worst. Second, tell students that, according to EPA WaterSense, a faucet dripping once every second can waste more than 3,000 gallons in a year, then ask which of the five fixtures comes closest to that speed and what that suggests about the other four.
  8. The activity ends when the ranking chart is complete and the class has agreed on which fixture the custodian should repair first. Keep the chart posted for the extension below.
Leak Patrol: A Drip-Count Station Rotation at Carrigan School — Grade 4 Health & Consumer Science
Name: ____________________________ Date: ______________

Student Handout

Imagine the five leaking fixtures at Carrigan School. Answer each question and show your work.

  1. The Room 12 sink drips 15 times in one minute. How many times does it drip in one hour, which is 60 minutes?
  2. The gym hallway fountain drips 24 times in one minute. How many times does it drip in one hour?
  3. The cafeteria hand sink drips 8 times in one minute. How many times does it drip in one hour?
  4. The custodian's mop sink drips 32 times in one minute. How many times does it drip in one hour?
  5. The playground spigot drips 45 times in one minute. How many times does it drip in one hour?
  6. Look at your five answers. Which fixture drips the most in one hour, and how many drips is that?
  7. The playground spigot drips 2,700 times in one hour. How many times does it drip in 6 hours?
  8. A faucet that drips once every second drips 60 times in one minute. Which of the five fixtures is closest to that speed?
  9. The mop sink drips 32 times a minute and the Room 12 sink drips 15 times a minute. How many more times does the mop sink drip in one minute?
  10. Explain in one or two sentences why a leak that looks slow can still waste a great deal of water in a year.

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: 900 drips.
    15 x 60 = 900 drips in one hour. Students may compute 15 x 6 = 90 and then attach the zero.
  2. Answer: 1,440 drips.
    24 x 60 = 1,440 drips in one hour.
  3. Answer: 480 drips.
    8 x 60 = 480 drips in one hour.
  4. Answer: 1,920 drips.
    32 x 60 = 1,920 drips in one hour.
  5. Answer: 2,700 drips.
    45 x 60 = 2,700 drips in one hour.
  6. Answer: 2,700 drips.
    The playground spigot has the largest hourly total at 2,700 drips, which matches its largest one-minute count of 45.
  7. Answer: 16,200 drips.
    2,700 x 6 = 16,200 drips over six hours.
  8. Answer: The playground spigot.
    At 45 drips per minute it is nearest to 60 drips per minute, since the next closest count is 32.
  9. Answer: 17 drips.
    32 - 15 = 17 more drips each minute at the mop sink.
  10. Answer: Each minute adds another count, and the minutes keep adding up all day and all year.
    Credit any answer that connects the small per-minute number to the large number of minutes in a day or a year, such as noting that even 8 drips a minute became 480 in a single hour.

Differentiation

Support

Give these students a printed multiplication chart and a worked model of 15 x 60 taped inside the handout, and let them use repeated addition of 60 for the first station before switching to multiplication. Pair them with a partner who records while they compute, so the rotation pace does not become the obstacle.

Extension

Ask students to convert their hourly totals to daily totals by multiplying by 24, then to write a two-sentence note to the custodian that names the fixture to repair first and gives the daily drip count as the reason. Students who want a further challenge can order the five daily totals and describe the gap between the largest and the smallest.

ELL supports

Print each fixture card with a simple sketch of the fixture beside its name, and post a word bank with "drip," "leak," "faucet," "spigot," and "per hour" near the ranking chart. Give the sentence frame "The ___ drips ___ times in one hour" for students to complete aloud at each station before writing.

Extensions

Take the rotation into the building with permission from the custodian. Small groups visit real fixtures with a timer and a tally sheet, count drips for one full minute, and bring the counts back to compute hourly totals the same way they did at the stations. Because real counts vary from minute to minute, have each group count twice and discuss what to do when the two counts disagree.