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Classroom activity Grade 1 Engineering & Design

Snapdragon Row's Leaf-Proof Drain Grate: A Grade 1 Design Shop

A grade 1 build-and-test rotation where teams cut a cardboard storm drain grate that lets rain through while holding back the leaves that clog the schoolyard drain.

Objectives

  1. Students will cut a grate with holes and explain why they chose that hole pattern.
  2. Students will test two grates with the same leafy water and compare what each one did.
  3. Students will name one change that would make their grate work better.

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.
Catch basin
A catch basin is a storm drain inlet with a sump underneath that traps sediment, leaves, and trash before water flows on into the storm sewer pipe. Crews periodically clean out catch basins so they do not clog or send debris downstream.

Teacher overview

This is a build-and-test design shop for the whole class, run in teams of three, in which each team cuts a cardboard cover for a storm drain and then tests it. The model maps onto the real problem directly: the cardboard square is the grate, the cut-out cup beneath it is the drain pipe, and the tub below is where the water is supposed to end up. Leaves held on top of a team's grate never reach the pipe, while water pooling on top shows that the holes were too small or too few. In the make-believe town of Snapdragon Row, the schoolyard drain backs up every autumn, which gives the class a reason to care about the trade-off between big holes and small ones.

Prep takes about fifteen minutes: cut the cardstock squares, cut the bottoms out of the cups, and set up two identical test stations so teams are not waiting in a long line.

Activity Directions

  1. Before class, set up two test stations. At each one, place a tub, a bottomless cup standing upright in the tub as the drain pipe, a pitcher of water, and a pile of leaves. Set the leftover cardstock, scissors, hole punches, and crayons at a separate build table.
  2. Gather the class and describe the problem in one or two sentences: at Snapdragon Row School the drain by the kindergarten door fills with leaves every fall, the water backs up, and the door gets a puddle in front of it. Ask what the class thinks a cover would need to do. Write the two jobs on chart paper: let the water through, keep the leaves out.
  3. Put students in teams of three and give each team two cardstock squares. Assign roles: one cutter, one leaf keeper, one pourer. Tell teams the roles will switch after the first test.
  4. Build round one, about ten minutes. Each team makes its first grate by punching or cutting holes in one square. Set one rule: the whole square has to stay in one piece. Teams color a border on their grate so they can find it later.
  5. Send teams to the test stations two at a time. A team sets its grate on top of the cup, sprinkles ten leaves onto the grate, and pours one cup of water slowly over the leaves. Teammates watch and say out loud what they see. Set the used grate on the drying towel with the team's name.
  6. Build round two, about ten minutes. Teams switch roles and cut a second grate that changes one thing about the first: bigger holes, more holes, or holes in a different place. Ask each team to say aloud which one thing they changed before they cut.
  7. Test round two the same way, with ten leaves and one cup of water, so the comparison is fair.
  8. End the shop when every team has tested both grates. Line the grates up along a table with each team's two side by side.
  9. Debrief on the rug with the Student Handout questions. Close by asking the class the two jobs from step 2 again and having students point to a grate on the table that does both.
Snapdragon Row's Leaf-Proof Drain Grate: A Grade 1 Design Shop — Grade 1 Engineering & Design
Name: ____________________________ Date: ______________

Student Handout

Read aloud with the class, one question at a time, after both tests are done.

  1. Did the water go down through your grate? Write yes or no.
  2. Did your leaves stay on top of your grate? Write yes or no.
  3. You made two grates. Which one held back more leaves? Tell how you know.
  4. Look at the holes you cut. Tell one way their size helped or hurt.
  5. Draw one change you would make to your grate. Tell why you would make that change.

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: Answers vary by team.
    Expect yes from teams whose holes were open enough to drain. A no here is useful evidence, not a failure, and should lead into question 4.
  2. Answer: Answers vary by team.
    Teams with small or narrow holes usually report yes. Teams with one large opening usually report that leaves washed through with the water.
  3. Answer: Answers vary by team, with a reason drawn from the test.
    Look for a comparison of the two grates that names what was seen, such as the second grate holding more leaves because its holes were smaller.
  4. Answer: Bigger holes drained faster but let leaves through, and smaller holes held leaves but drained slower. Accept either half of the trade-off in a student's own words, tied to what happened at the test station.
  5. Answer: Answers vary.
    Accept any drawing with a stated change and a reason, such as adding more small holes so the water still gets through while the leaves stay on top.

Differentiation

Support (below grade level)

Pre-punch a starter hole in the center of the square so scissors have somewhere to begin, and offer two grate patterns on cards, one with many small holes and one with a few large holes, for students to copy rather than invent. Let these students be the leaf keeper during the first test so they watch closely before they build.

Extension (above grade level)

Ask these students to design a grate for a drain that gets sticks and litter as well as leaves, and to explain what they changed for the bigger debris. They can also test a third grate with twice as many leaves and report whether the same design still works.

ELL supports

Pre-teach five words at the test station with the objects in hand: drain, grate, hole, leaf, pour. Post a two-picture card labeled water goes through and leaves stay on top, and let teams point to it when reporting results. Handout questions 1 and 2 are yes-or-no by design, and questions 3 through 5 may be answered with a labeled drawing or spoken aloud while an adult scribes.

Extensions

Walk the class to a real storm drain on or near school grounds, look through the grate together from a safe distance, and count what has collected on top of it. Students can sketch that real grate beside their own design and mark one thing the real one does that theirs did not.