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Classroom activity Kindergarten Math

Rain Race: A Kindergarten Relay Comparing Two Downspouts

A kindergarten movement activity where students compare two pool-noodle downspouts by length, race pom-pom raindrops down them, and solve a debrief subtraction story.

Objectives

  1. Students will directly compare the length of two downspouts and identify which is longer and which is shorter.
  2. Students will count a group of objects split evenly between two teams, up to 10.
  3. Students will solve a subtraction word problem within 10 about objects lost during the race.

Vocabulary

Downspout
A downspout is the pipe that carries rainwater down from a roof's gutters to the ground. Where that water goes next, whether onto a lawn, into a rain barrel, or straight to a storm drain, makes a big difference in how much runoff a property sends downstream.

Also: longer, shorter, compare

Teacher overview

This is a whole-class movement activity for about 10 students at a time, though it can be run in two rotating groups for a larger class. Two open channels made from cut pool noodles stand in for the downspouts that carry rainwater off a real roof, one propped longer and gentler and one propped shorter and steeper. Before any racing happens, the class directly compares the two downspouts by length, the exact skill this activity teaches: deciding which of two objects has more or less of a shared measurable attribute, in this case length, by looking at them side by side rather than guessing.

Activity Directions

  1. Before class, cut two foam pool noodles in half lengthwise to make two open channels. Leave one at its full length and cut the other to about half that length. Prop the long one from a taller chair seat down to the floor at a gentle angle, ending where Bucket A will go. Prop the short one from a lower stool down to the floor at a steeper angle, ending where Bucket B will go.

  2. Gather the whole class in a half-circle facing both downspouts, with the buckets not yet in place. Hold the two downspouts side by side, one in each hand, lining up one end. Ask: "Which downspout is longer? Which one is shorter?" Let two or three students point and explain how they can tell.

  3. Explain how the activity works: "On a real house, rain lands on the roof and runs down a downspout like these to reach the ground. Today, each of you gets to be a raindrop racing down one of these downspouts." Place a bucket under the lower end of each downspout.

  4. Split the class into Team A, at downspout A, and Team B, at downspout B, with 5 students on each team. If a class has a different total number of students, split it as evenly as possible and use the new team size in the debrief math below instead of 5.

  5. Give each team 5 pom-pom raindrops, one per student, for 10 pom-poms total. One student at a time places a pom-pom at the top of their team's downspout and releases it, watching it roll down into the bucket while the rest of the class counts out loud.

  6. Continue rotating turns until every student on both teams has released one pom-pom, for 10 total raindrop races.

  7. Gather the class back into the half-circle once all 10 pom-poms have raced. Ask the following four debrief questions in order, letting students answer aloud before moving to the next one:

    1. Which downspout is longer, Downspout A or Downspout B?
    2. Team A raced 5 pom-poms and Team B raced 5 pom-poms. How many pom-poms raced in all?
    3. Suppose 2 of the 10 pom-poms rolled off the side instead of reaching a bucket. How many pom-poms landed in a bucket?
    4. Why does water reach the ground faster on the short, steep downspout than on the long, gentle one?

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: Downspout A. When the two downspouts were held side by side with one end lined up, Downspout A stuck out past the end of Downspout B, so Downspout A is longer.
  2. Answer: 10 pom-poms. 5 pom-poms started on Team A plus 5 pom-poms started on Team B is 5 + 5 = 10 pom-poms in all.
  3. Answer: 8 pom-poms. If 2 of the 10 pom-poms rolled off the side instead of reaching a bucket, then 10 − 2 = 8 pom-poms landed safely in a bucket.
  4. Answer: A short, steep downspout gives rainwater a quicker, steeper drop, while a long, gentle downspout gives the water a longer path to travel before it reaches the ground.

Differentiation

Support

Let students who need extra support hold both downspouts together with a partner during the length comparison, feeling the extra length of the longer one with their hands. During counting, provide a printed strip of 10 boxes so students mark one box for each pom-pom that races.

Extension

Ask confident students to predict, before racing, which downspout they think will let a pom-pom reach the bucket faster, and to explain their prediction using the words "longer" and "shorter" before testing it.

ELL supports

Pre-teach longer, shorter, and downspout using the two actual pool-noodle pieces held up side by side, with a simple gesture (arms stretched wide for longer, hands close together for shorter). Allow students to answer the length comparison by pointing instead of speaking a full sentence.

Extensions

On a rainy day, take the class to look at a real downspout on the school building and compare its length to the pool-noodle downspouts used in the activity. Ask students to sketch a downspout of their own design, longer or shorter than the two used in class, and explain why they chose that length.