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Classroom activity Kindergarten Science

Race to the Drain: A Kindergarten Storm Drain Design Race

A kindergarten activity where small groups test two cardboard channel designs, racing a cotton-ball raindrop into a cup drain to compare which design works better.

Objectives

  1. Students will describe a playground puddling problem that a channel to a drain could help solve.
  2. Students will test two channel designs by racing a raindrop down each one to a drain cup.
  3. Students will compare the two test results and identify which design worked better.

Vocabulary

Key words: channel, drain, design

Teacher overview

At the fictional Redwood Kindergarten, used for this activity, rain pools right by the classroom doors because there is no path carrying it away. This activity puts students in charge of testing two channel designs that could carry a "raindrop" (a cotton ball) away from the doors and into a cup labeled Storm Drain. The activity teaches the concept directly: each channel is a small model of a real stormwater channel, and racing the same raindrop down two different shapes lets students see, with their own eyes, that a channel's design changes how fast and how well water reaches the drain. A common idea this activity corrects is that any path to a drain works equally well; comparing a straight channel to a zigzag one shows students that shape changes the result.

Run this in small groups of 3 to 4 so every student gets a turn placing the raindrop, timing the race, or recording the group's result.

Activity Directions

  1. Gather the class near a picture or a small floor model of Redwood Kindergarten's flooded doorway. Ask: "What is the problem here, and what could help the rain go somewhere else instead of pooling by the door?" Take a few answers before introducing the word channel: a path that guides water from one place to another.
  2. Show the class two channel designs, built ahead of time: Channel A is one straight ramp from a high point down to the drain cup. Channel B has two gentle turns along the way, making a zigzag path to the same drain cup.
  3. Put students into groups of 3 to 4. Give each group one Channel A, one Channel B, two cotton-ball raindrops, and one drain cup placed where both channels end.
  4. Have one student place a raindrop at the top of Channel A while another student says "Go!" Time how many seconds it takes to reach the drain cup, or count out loud together, "1, 2, 3."
  5. Repeat with a fresh raindrop on Channel B, timing or counting the same way.
  6. Compare: did the raindrop reach the drain cup faster on Channel A or Channel B? Did either raindrop fall off the side of its channel before reaching the cup?
  7. On the two-column recording page, each group draws a simple check mark under whichever channel got their raindrop to the drain cup faster and without falling off.
  8. Groups that finish early may test a third channel shape of their own design, using a fresh raindrop, if time and materials allow.
  9. End the activity after every group has tested both Channel A and Channel B and marked a result on their recording page, roughly 18 minutes into the session; gather the class for the debrief.

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. Step 6 comparison: Which channel was faster? Answer: In most groups' tests, Channel A (the straight ramp) carries the raindrop to the drain cup faster, because a straight path has no turns to slow the raindrop down or send it off course.
  2. Debrief question: "Which channel got your raindrop to the drain fastest, and why do you think it worked better?" Answer: Channel A usually worked faster because it has no turns; accept any answer that correctly identifies the channel the group actually observed as faster, with a reason about its shape.
  3. Debrief question: "What might happen at Redwood Kindergarten's door if there were no channel at all carrying the rain away?" Answer: The rain would keep pooling right by the door, the same puddling problem described at the start of the activity, which is why building a channel to a drain matters.

Differentiation

Support

Pre-build both channels before class so students only need to place the raindrop, time the race, and compare, rather than assembling the channels themselves. Provide a simple two-picture choice card (fast channel / slow channel) for the recording page instead of a drawn check mark.

Extension

Ask groups to design and test a third channel using an idea of their own (a steeper ramp, a channel with a bump), predict which of the three will be fastest before testing, and explain their prediction using the word "because." Have them count and compare the exact number of seconds each of their three channels took.

ELL supports

Pre-teach channel, drain, and design with a simple before-and-after picture of a puddled doorway becoming a channel that carries the water away. Allow students to show their comparison answer by pointing to the faster channel rather than saying a full sentence, and pair the word "channel" with the physical action of tracing a path with a finger.

Extensions

Look at any real gutters, storm drains, or channels visible around the school building and talk about which shape they most resemble, Channel A or Channel B. Extend the activity at home by having students build a simple channel from a paper towel tube that a parent cuts in half and test it together with a cup of water, then report back what they saw the next day.