Classroom activity Kindergarten Science

Mallard Pond Clean-Up: A Kindergarten Sorting Relay Game

A kindergarten relay game where two teams race to collect only the litter scattered near a fictional pond, then count and compare their totals.

Grade: Kindergarten
Subject: Science
Material: Classroom activity
Time: 25 min
Prep: Low prep
Materials: A large taped outline on the floor representing Mallard Pond, 12-16 litter cards or safe props (a bottle cap, a wrapper, a paper cup) and an equal number of natural object cards (a leaf, a stick, a rock, a feather), scattered inside the taped area, 2 team collection bags or bins, labeled Team A and Team B, A timer

Standards

K-ESS3-3 NGSS

Communicate solutions that will reduce the impact of humans on the land, water, air, and/or other living things in the local environment.

How this material aligns: Teams physically collect litter cards from the taped pond area while leaving natural object cards alone, acting out one real solution that reduces human impact on a shared water source.

All materials for K-ESS3-3 →

K.CC.B.4 Common Core Math

Understand the relationship between numbers and quantities; connect counting to cardinality: a. When counting objects, say the number names in the standard order, pairing each object with one and only one number name and each number name with one and only one object. b. Understand that the last number name said tells the number of objects counted. The number of objects is the same regardless of their arrangement or the order in which they were counted. c. Understand that each successive number name refers to a quantity that is one larger.

How this material aligns: After the relay, each team counts its collected litter cards one at a time and states the last number as its total, the connect-counting-to-cardinality task this standard describes.

All materials for K.CC.B.4 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-07-16.

Objectives

Students will sort litter from natural pond objects during a timed relay.
Students will collect only litter, leaving natural objects in place, to model a real clean-up action.
Students will count their team's collected litter and state the total, then compare it to the other team's total.

Vocabulary

Key words: litter, pond, collect

Teacher overview

Mallard Pond, a fictional pond used for this activity, has litter mixed in among its leaves, sticks, and rocks after a windy weekend, and this relay puts two teams in charge of the clean-up. The activity teaches the concept directly: only litter cards may be collected and carried back to a team bin, while natural object cards must stay exactly where they are, so students practice telling the difference between trash that hurts the pond and objects that naturally belong there. A common mix-up this game corrects is scooping up everything in sight; a runner who grabs a leaf or a rock by mistake must set it back down inside the pond outline before returning to the line.

Run this with two teams of equal size lined up at opposite ends of the taped pond area, with each team's bin placed at their own starting line.

Activity Directions

Explain the problem: after a windy weekend, litter blew into Mallard Pond and got mixed in with the leaves, sticks, and rocks that belong there naturally. Show the class one litter card and one natural-object card side by side and ask students to name the difference.
Scatter the litter cards and the natural object cards evenly inside the taped pond outline before the relay begins.
Split the class into Team A and Team B, lined up at opposite ends of the pond area, each with their own empty bin.
On "Go," the first runner from each team jogs into the pond area, picks up exactly one card, and decides: is it litter? If yes, carry it back and drop it in the team bin. If it is a natural object, set it back down inside the pond outline instead.
As soon as one runner returns, the next runner in that team's line goes, continuing the relay until the timer ends or all the litter cards have been collected.
If a runner accidentally brings back a natural object, pause them gently and have them return it to the pond outline before tagging the next runner.
End the relay after 3 minutes on the timer or once every litter card has been collected by one team or the other, whichever comes first.
Gather both teams around their bins for the counting and 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

Debrief task: Each team counts its collected litter cards one at a time and says the last number counted as its total. Answer: Accept whatever real total each team reaches; the key skill is that the last number named tells the size of the whole pile, no matter the order the cards were counted in.
Debrief question: "Which team collected more litter cards, and how do you know?" Answer: The team with the greater total collected more; students should compare the two counted totals directly to decide, the same way two counted groups are compared in math.
Debrief question: "Why did we leave the leaves, sticks, and rocks in the pond instead of collecting those too?" Answer: Leaves, sticks, and rocks naturally belong at a pond and are part of a healthy home for the ducks and other animals living there, unlike litter, which does not belong and can hurt them.

Differentiation

Support

Reduce the number of scattered cards to 8 total (4 litter, 4 natural) and pair each runner with a partner who points at the card before it is picked up. Use a simple color code, red cards for litter and green cards for natural objects, so students can sort by color at a glance.

Extension

Ask faster teams to also sort their collected litter cards into smaller categories once the relay ends, such as "paper" and "plastic," and count each smaller group. During the debrief, have these students explain in a full sentence why a specific card counts as litter rather than a natural object.

ELL supports

Pre-teach litter, pond, and collect using a simple picture of a clean pond next to a littered one, pointing to each while naming it. Allow students to participate fully through the physical sorting action, and accept a pointing gesture toward the team bin with more cards for the comparison debrief question.

Extensions

If a real pond, creek, or drain area is safely accessible near the school, take the class on a short, adult-supervised litter walk with gloves and a bag, keeping students well back from the water's edge and leaving any sharp or broken item for an adult, applying the same only-collect-litter rule from the game to a real space. Keep a running class tally across several rounds of the game played on different days, adding each round's totals to a shared chart and comparing which day the class collected the most litter cards.