Lesson plan Grade 1 Science

Where Does the Puddle at Whistling Pines Go? A Grade 1 Lesson

A grade 1 science lesson in three short visits: students pour a puddle on sunny blacktop, trace it in chalk, and measure it shrinking in craft-stick units.

Grade: Grade 1
Subject: Science
Material: Lesson plan
Time: 3 sessions, ~48 min total
Prep: Low prep
Materials: A half-gallon jug or pitcher of water (about 2 liters) for making the class 'pretend puddle', A flat, sunny patch of blacktop away from drains, cracks, slopes, and traffic, used on a dry, sunny day, Sidewalk chalk in three different colors, About 12 jumbo craft sticks that are all the same length (same-size unsharpened pencils also work), A class chart with three rows (Morning, Later, After lunch) and two columns (Chalk color, Craft sticks wide), A picture or drawing of a puddle on a sidewalk, Three picture cards for the exit ticket: the air, a drain, and the ground, Drawing paper or a simple recording page for each student

Standards

1.MD.A.2 Common Core Math

Express the length of an object as a whole number of length units, by laying multiple copies of a shorter object end to end; understand that the length measurement is the number of same-size length units that span it with no gaps or overlaps.

How this material aligns: Students lay same-size craft sticks end to end, with no gaps or overlaps, along a chalk line across the class blacktop puddle at two different times of day, expressing its width each time as a whole number of length units.

All materials for 1.MD.A.2 →

W.1.3 Common Core ELA

Write narratives in which they recount two or more appropriately sequenced events, include some details regarding what happened, use temporal words to signal event order, and provide some sense of closure.

How this material aligns: Students recount the puddle's day as two or more sequenced events using temporal words such as first, next, and then, in the closing writing task of the procedure.

All materials for W.1.3 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-10-12.

Objectives

Students will measure the width of a real puddle in craft-stick units at two different times of day.
Students will recount the puddle's day in order using temporal words like first, next, then, and last.
Students will explain in their own words that the sun's warmth causes water to evaporate into the air.

Vocabulary

Key words: puddle, evaporate, measure, shrink

Teacher overview

After it rains at Whistling Pines Elementary, puddles form on the blacktop and then, by the end of the school day, many of them are gone. In this lesson the class makes its own puddle by pouring a jug of water onto a flat, sunny patch of blacktop, traces its edge in chalk, and measures its width with craft sticks laid end to end, then returns about an hour later and again after lunch to trace and measure it again. A puddle on blacktop is deepest in the middle and very thin at its edges, so as the sun warms the water and the level drops, the thin edges dry first and the puddle visibly pulls inward, leaving a band of dry blacktop between the chalk lines. A common misconception is that the water simply "dries up" and disappears completely; the lesson introduces the more accurate idea that the water turns into an invisible gas, called water vapor, and goes into the air.

Plan the lesson for a dry, sunny morning, and make the first visit by mid-morning so the puddle has several hours of sun. How fast the puddle shrinks depends on the day: on a hot day it may be gone within an hour or two, so make the second visit after about 30 minutes, while on a cool or hazy day it shrinks more slowly and may still be there after lunch. Either result works for the lesson, because the chalk lines stay on the blacktop as a record of each visit. Choose a spot with no drain or crack nearby, so that the water cannot run or soak away and the exit-ticket answer stays clear.

Procedure

First visit, mid-morning on a sunny day.

Hook (5 min): In the classroom, show a picture or drawing of a puddle on a sidewalk. Ask: "What do you think happens to a puddle after a few hours? Where does the water go?" Collect three or four guesses without correcting them yet, and tell students the class is going to make its own puddle to find out.

Make the puddle (7 min): Outside, pour the jug of water slowly onto the chosen patch of blacktop and wait about a minute until the water stops spreading. Trace all the way around the edge of the water with the first chalk color. Then draw one long, straight chalk line across the widest part of the puddle, starting and ending on dry blacktop beyond the water. The chalk may look faint where it crosses the water, so press firmly and make both ends clear on the dry blacktop. This is the measuring line, and the class will measure along it every time so that each measurement is taken in the same place.

First measurement (6 min): With students watching and counting aloud, lay craft sticks end to end along the measuring line from one edge of the water to the other, with no gaps and no overlaps. If the last stick would hang partly past the edge, ask the class whether it is closer to a whole stick or to no stick, and record the nearest whole number as "about" that many sticks (for example, about 6 craft sticks). Write the number and the chalk color on the class chart in the "Morning" row.

Evaporate and predict (4 min): Back in the classroom, introduce the word evaporate: when the sun warms water, some of the water turns into an invisible gas called water vapor and goes into the air. Ask students to predict whether the puddle will be wider, narrower, or the same width at the next visit, and to show their prediction with their hands (hands apart for wider, hands together for narrower, and hands still for the same).

Second visit, about one hour later (about 30 minutes later on a hot day).

Second measurement (7 min): Return to the puddle and trace its new edge with the second chalk color. Ask students what they notice between the two chalk lines; they should see a band of dry blacktop where water used to be. Measure along the same measuring line in the same way and record the new number in the "Later" row (for example, about 4 craft sticks). If the puddle is already gone, record 0 and point out that only the chalk lines are left.

Third visit, after lunch.

Last look (3 min): Walk past the puddle spot as a class. If any water is left, trace its edge with the third chalk color and measure it along the measuring line; if it is gone, record 0 in the "After lunch" row. Ask students where the water could have gone, and help them notice three things: it is not on the blacktop, it did not run away (the chalk lines show that the edge only moved inward), and there is no drain nearby for it to go down.

Compare and explain (4 min): In the classroom, read the chart together from top to bottom and ask: "Did the puddle get wider or narrower? How many craft sticks narrower was it at the second visit than at the first?" In the example run, it was 2 sticks narrower, because 6 take away 4 is 2. Then ask students to explain, using the word evaporate, where the water went. Listen for the idea that the sun warmed the water and it went into the air as water vapor.

Writing (7 min): Each student draws or writes a story of the puddle's day with at least two events in order, using temporal words, such as "First the puddle was 6 sticks wide. Next the sun warmed it. Then it was 4 sticks wide. Last it was gone." Students use the numbers from the class chart. Circulate to scribe captions for students who dictate their story aloud.

Closure / exit ticket (5 min): Ask one question aloud: "Where did the water in the puddle go?" Students answer orally or point to a picture card: into the air, down a drain, or into the ground. The correct answer is into the air. If fewer than half the class answers correctly, plan to revisit the chalk lines briefly the next day and retell the puddle's day together before starting a new lesson.

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Answer Key

The craft-stick counts are measurements of the class's own puddle, so the exact numbers depend on the weather, the blacktop, and the sticks a class uses. The values below are the illustrative counts from the example run in the procedure (about 6 sticks in the morning, about 4 sticks an hour later, and gone after lunch). Look for the recording method and the direction of the change rather than a single fixed number.

First measurement, what to look for: Students lay same-size craft sticks end to end along the chalk measuring line from one edge of the water to the other, with no gaps or overlaps, count them together, and record that whole number on the chart in the "Morning" row. In the example run, this comes to about 6 craft sticks.
Second measurement, what to look for: The class measures along the same chalk line in the same way and records the new whole number in the "Later" row. The second count should be smaller than the first, and a band of dry blacktop should be visible between the two chalk lines. In the example run, the puddle goes from about 6 craft sticks to about 4 craft sticks, which is 2 sticks narrower, and it is gone (0) by the after-lunch visit.
Why the puddle got narrower (teacher reference): A puddle on blacktop is thin at its edges and deeper in the middle. As the sun warms the water, some of it evaporates and the water level drops, so the thin edges dry out first and the edge moves inward. A first grader's version is enough: "The sun warmed the water and it went into the air, so the puddle got smaller."
Exit ticket answer: Into the air. The sun warmed the water and turned it into an invisible gas called water vapor, which went into the air, so the puddle got smaller and then disappeared instead of the water simply vanishing.

Differentiation

Support

Provide a sentence frame for the writing task: "First the puddle was ___ sticks wide. Then it was ___ sticks wide." Allow students to fill in the two numbers from the class chart rather than composing an original sentence. During measuring, let these students hand the craft sticks to the teacher one at a time while the class counts.

Extension

Ask confident students to predict, before the second visit, how many craft sticks wide the puddle will be and to explain their reasoning. After the measurement, have them compare their prediction to the actual count and say how many sticks narrower the puddle became.

ELL supports

Pre-teach "puddle," "evaporate," "measure," and "shrink" with gestures: cupped hands for puddle, fingers wiggling upward for evaporate, hands laying sticks end to end for measure, and hands moving closer together for shrink. Point to the chalk lines while saying "the puddle shrank." Allow students to answer the exit ticket by pointing to a picture card instead of speaking a full sentence.

Extensions

On another sunny day, pour two equal jugs of water, one on blacktop in full sun and one on blacktop in the shade of the building, and trace and measure both puddles at the same times. Students can compare which puddle shrank faster and connect the difference to the sun's warmth. After the next rain, once the sun comes out, students can also trace a real puddle on the playground in chalk (with adult supervision) and check it again before dismissal to see whether the same shrinking pattern happens.