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Classroom activity Grade 2 Math

Rain Garden or Storm Drain? A Grade 2 Sorting Relay at Marlowe

A 30-minute grade 2 relay game where two teams sort surface picture cards into Rain Garden or Storm Drain bins, then graph and compare their correct-sort totals.

Objectives

  1. Students will sort pictures of surfaces into categories based on whether rain soaks in or runs off.
  2. Students will count and compare two teams' correct-sort totals.
  3. Students will draw and interpret a two-bar graph of the relay results.

Vocabulary

Rain garden
A rain garden is a shallow planted dip in the ground that catches rain running off a roof or driveway and lets it soak slowly into the soil. Its deep-rooted plants help clean the water.
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: soak in, run off

Teacher overview

This is a whole-class relay for two teams of equal size, played in a gym or an open classroom space at Marlowe Elementary (a fictional school used for this activity). Two pairs of bins are set up, one pair per team, each labeled Rain Garden and Storm Drain. Rain that lands on a surface like a lawn or a garden bed soaks into the ground and gets filtered by plant roots, while rain on a surface like a driveway or a parking lot runs off fast, often carrying trash straight to a storm drain and then to a creek or river. Each team races to sort a deck of surface picture cards into the correct bin, turning the difference between these surfaces into an active game the whole class plays together.

Activity Directions

  1. Before class, label two bins or hoops "Rain Garden" and "Storm Drain" for each team, and prepare two identical decks of 12 surface picture cards, one for each team (see the Student Handout for the full list). Read the concept aloud once: surfaces that let rain soak into the ground, like a lawn or a garden bed, go in the Rain Garden bin; surfaces that make rain run off fast, like a driveway or a parking lot, go in the Storm Drain bin.
  2. Divide the class into Team A and Team B, and have each team line up single file behind its own shuffled deck of 12 cards, placed face down on a table.
  3. On "go," start the timer. The first student in Team A's line runs to the table, turns over the top card, decides Rain Garden or Storm Drain, places it in the matching bin, and runs back to tag the next teammate, who repeats the process with the next card.
  4. Team A's relay ends once all 12 cards have been placed in a bin, or after 3 minutes, whichever comes first. Record Team A's time and pause the game.
  5. Repeat steps 3 and 4 for Team B with their own separate deck of 12 cards.
  6. With the class watching, check each team's bins against the card lists in the Student Handout and count how many cards each team placed correctly.
  7. Lead the debrief: as a worked example, tell students, "Suppose Team A sorted 10 cards correctly out of 12, and Team B sorted 11 correctly out of 12." Have students draw a two-bar graph of these example totals on grid paper, then answer the four numbered debrief questions on the Student Handout, first for these example totals and then for the actual class results.
Rain Garden or Storm Drain? A Grade 2 Sorting Relay at Marlowe — Grade 2 Math
Name: ____________________________ Date: ______________

Student Handout

Surface cards (12 per team):

  • Rain Garden (soaks in): lawn, garden bed, mulch, dirt path, gravel bed, wood chips
  • Storm Drain (runs off): driveway, parking lot, sidewalk, rooftop, paved road, tennis court

Debrief questions:

For questions 2 and 3, use the worked-example results: Team A sorted 10 cards correctly, and Team B sorted 11 cards correctly.

  1. Count the two card lists above. How many cards belong in the Rain Garden bin, and how many belong in the Storm Drain bin?
  2. How many more cards did Team B sort correctly than Team A?
  3. How many cards did both teams sort correctly altogether?
  4. Why does a rain garden help keep a storm drain from overflowing during a big rainstorm?

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: 6 cards belong in the Rain Garden bin (lawn, garden bed, mulch, dirt path, gravel bed, wood chips), and 6 cards belong in the Storm Drain bin (driveway, parking lot, sidewalk, rooftop, paved road, tennis court).
  2. Debrief question: "Using the example results (Team A: 10 correct out of 12, Team B: 11 correct out of 12), how many more cards did Team B sort correctly than Team A?" Answer: 1 more card. 11 minus 10 equals 1.
  3. Debrief question: "How many cards did both teams sort correctly altogether, using the example results?" Answer: 21 cards. 10 + 11 = 21.
  4. Debrief question: "Why does a rain garden help keep a storm drain from overflowing during a big rainstorm?" Answer: A rain garden lets rain soak into the ground slowly instead of all of it rushing to the storm drain at once, so the drain has less water to carry away during a heavy rain.

Differentiation

Support

Reduce each team's deck to 8 cards (4 Rain Garden, 4 Storm Drain) and post a picture-only answer key at each bin so students can self-check as they sort.

Extension

After the relay, challenge students to sort three additional "tricky" surfaces, such as a gravel driveway, a grass strip between sidewalk squares, and a green roof, and defend their bin choice to the class.

ELL supports

Use picture-only cards (no printed words) for every student, and pair the spoken direction "soaks in" or "runs off" with a simple hand gesture (fingers wiggling downward for soaks in, a flat sweeping hand for runs off) that the whole class performs together before the relay starts.