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Classroom activity Grade 3 Science

Ranking Three Cleanup Plans for Marlden Brook: A Grade 3 Activity

A 45-minute grade 3 activity in which groups rank three cleanup plans for a made-up brook against three posted conditions and defend a final pick.

Objectives

  1. Students will describe what each of three cleanup plans does to dirty runoff.
  2. Students will rank three plans against one stated condition at a time.
  3. Students will choose one plan and give two reasons drawn from the cards.

Vocabulary

Storm drain
A storm drain is the grate at the edge of a street that swallows rainwater and sends it through pipes to the nearest creek or river. That water is usually not treated, so only rain belongs down the drain.

Also: runoff, bank, pasture, plan, rank

Teacher overview

This is a small-group ranking activity for groups of four, run on a floor line marked with tape. Each group holds the same three cleanup plans for a fictional brook and physically places them in order along the line, once for each of three posted conditions, so a plan that wins under one condition visibly loses under another. Moving the same three cards three times is what carries the lesson, which is that an engineering choice is a comparison against stated conditions rather than a search for one right answer. The activity ends with a class vote and a written pick.

Activity Directions

  1. Set up (5 min). Run a strip of masking tape across an open floor and label one end "best" and the other end "worst." Post the three condition signs where every group can read them. Give each group of four a set of three plan cards and each student a handout.
  2. Read the plans (8 min). Groups read the three plan cards aloud, one card per student, with the fourth student underlining what each plan actually does to the water. Students answer handout items 1 through 3 before any ranking begins.
  3. Round 1, dirt (8 min). Read condition A aloud: the plan should keep the most dirt out of the brook. Each group sends one member to lay its three cards along the tape line in order. Groups compare lines, and two groups that disagree explain their placements to each other.
  4. Round 2, upkeep (7 min). Read condition B aloud: the plan should take the least work to keep up each year. Groups reorder the same three cards on the line. Ask which card moved the farthest between the two rounds and why.
  5. Round 3, seasons (7 min). Read condition C aloud: the plan should help in every season, not only in summer. Groups reorder the cards a third time. Point out any plan that has now been first once and last once.
  6. Class vote and debrief (10 min). Each group states its final pick and one reason. Tally the votes on chart paper. Close with two questions: which condition mattered most to your group, and which plan would you add if the town could pay for two? Students then write their pick and two reasons in handout item 6.
Ranking Three Cleanup Plans for Marlden Brook: A Grade 3 Activity — Grade 3 Science
Name: ____________________________ Date: ______________

Student Handout

Marlden is a made-up town. Marlden Brook runs through it. The brook passes a cow pasture. Then it passes a store parking lot. Then it passes a park. Rain washes dirt and waste into the brook from all three places. The town wants to clean up the brook. Read the three plans.

Plan 1. Plant a wide strip of grass and shrubs along both banks. The strip catches dirt before the runoff reaches the water. Roots hold the bank in place. Volunteers must water the new plants for two summers.

Plan 2. Put wire baskets in the storm drains by the parking lot. The baskets catch trash and grit from the pavement. A worker must empty every basket each month, all year long.

Plan 3. Build a fence along the pasture so the cows cannot walk into the brook. The cows drink from a trough instead. Waste stays up in the field. A farmhand checks the fence after big storms.

Condition A. The plan should keep the most dirt out of the brook.

Condition B. The plan should take the least work to keep up each year.

Condition C. The plan should help in every season, not only in summer.

  1. Which plan puts something new inside the storm drains?
  2. Which plan keeps animals out of the water?
  3. Plan 1 plants a strip of grass and shrubs. What does that strip do to the dirt in the runoff?
  4. Which plan did your group rank first for Condition A? Tell why.
  5. Which plan takes the most work each year? Tell why.
  6. Your town can pay for only one plan this year. Which plan do you pick? Give two reasons from the cards.

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: Plan 2. The card says wire baskets go into the storm drains by the parking lot.
  2. Answer: Plan 3. The card says a fence keeps the cows out of the brook and gives them a trough instead.
  3. Answer: It catches the dirt. Accept any answer stating that the strip catches or slows the dirt before the runoff reaches the water, and give credit as well for noting that the roots hold the bank in place.
  4. Answer: Accept any of the three plans when the group gives a reason tied to Condition A. Plan 1 and Plan 3 are the strongest answers, since a bank strip catches dirt from every side and a fence stops waste at the pasture, while Plan 2 catches only what washes off the parking lot.
  5. Answer: Plan 2. The card says a worker must empty every basket each month, all year long, while Plan 1 needs watering for two summers only and Plan 3 needs a fence check after big storms.
  6. Answer: Accept any plan supported by two reasons taken from the cards or the conditions. Look for reasons that name what the plan does to the water and how much upkeep it needs, rather than reasons about which plan sounds nicest. A group that picks Plan 2 should be asked what happens to the dirt washing in from the pasture.

Differentiation

Support

Read all three plan cards aloud to these students before the group reading, and give them cards with the key sentence already highlighted. Let them rank only two plans at a time in each round, adding the third card after their partner explains it. Offer item 6 as a choice of three sentence strips they can copy and finish.

Extension

Ask these students to write a fourth plan for the fictional town, then rank all four against the three posted conditions and report where the new plan lands. Have them explain which condition their plan was designed to win and what it gives up in exchange.

ELL supports

Pre-teach "runoff," "bank," and "pasture" with a labeled drawing of the brook and its three neighbors. Post the three conditions as icons beside the words. Provide the frames "Plan ___ catches ___" and "I pick Plan ___ because ___ and ___," and let students answer items 1 and 2 by holding up the matching card.

Extensions

Have the class write a short group letter to the fictional Marlden town council recommending one plan, with each group contributing one sentence of evidence. Post the three ranking lines from the activity as photographs or sketches beside the letter so a reader can see how the same three plans ordered differently under each condition.