Lesson plan Grade 1 Science

Melting Milburn School's Snow Cups: A Grade 1 Water Cycle Lesson

Students pack snow to a marked line in a clear cup, let it melt, and measure with cubes how far the line drops to find the water stored in the snow.

Grade: Grade 1
Subject: Science
Material: Lesson plan
Time: 40 min
Prep: Low prep
Materials: Clear straight-sided plastic cups, two per group, Fresh snow, or crushed ice from a cooler if there is no snow outside, Connecting cubes, about fifteen per group, Stickers or a dry-erase marker for marking the snow line and the water line, A tray or towel under each group's cups, Craft sticks for leveling the snow

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 measure the snow line and the water line by stacking connecting cubes end to end beside the cup and reporting each height as a whole number of cubes with no gaps.

All materials for 1.MD.A.2 →

1.OA.A.1 Common Core Math

Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem.

How this material aligns: Handout items 3, 4, and 5 subtract the water line from the snow line in two cups and add the two snow lines, which are compare and put-together word problems within twenty.

All materials for 1.OA.A.1 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-09-04.

Objectives

Students will measure a snow line and a water line as a whole number of cubes.
Students will find how many cubes the line dropped in each cup by comparing the two heights.
Students will explain why melted snow fills far less of the cup than the snow did.

Vocabulary

Key words: snow, melt, cube, line

Teacher overview

The fictional Milburn School sits beside a field that holds snow all winter, and the town's water crew watches that field closely, because the snow on it is water waiting to run into the creek in spring. This lesson gives first graders a cup-sized version of the same measurement: pack snow to a line, mark the line with cubes, let it melt, then measure again. The misconception this lesson exists to correct is the strong and reasonable belief that a cup packed full of snow will melt into a cup full of water. Snow is mostly air held between the flakes, so the water line lands far below the snow line, and a class that has not seen this happen usually predicts the two lines to be nearly equal.

Procedure

Hook (5 min): Hold up a clear cup packed with snow and ask the class to point to the spot on the cup where they think the water line will be once it all melts. Mark two or three of the guesses on the outside of the cup with a marker, without telling students whether any guess is close.

Direct instruction (8 min): Show how to measure with cubes. Stand a tower of connecting cubes next to the cup, build it up to the snow line, then pull the tower off and count the cubes aloud. Stress that the cubes must sit end to end with no gaps and that counting starts at the bottom of the cup. Record the class demonstration cup on the board as a snow line of 9 cubes. A packed cup of snow takes a few hours to melt at room temperature, so early that morning pack a second demonstration cup to the same 9-cube line and set it in a warm spot; use that cup at the closure.

Guided practice (12 min): Remind the class that nobody eats the snow or drinks the melted water. Groups of three or four pack snow into their first cup, level the top with a craft stick, and measure the snow line in cubes. One student builds the cube tower, one reads the count, and one writes it on the group chart. Groups then set the cup on the tray to melt and repeat the whole procedure with a second cup so both cups are marked and recorded before any melting finishes.

Independent practice (10 min): While the cups melt, students work the numbered questions on the Student Handout, which carries the class record from the demonstration cups. Circulate and watch for students who subtract in the wrong direction on item 3; ask those students which line was taller before they write.

Closure and formative check (5 min): Measure the melted second demonstration cup together and write its water line next to the snow line already on the board. Ask every student to show with two fingers held apart how big the drop was, then have three students explain in a sentence why the line fell so far. If more than a few students still say the melted water should have filled the cup, hold two cups side by side, one of packed snow and one of the melted water, before moving on.

Melting Milburn School's Snow Cups: A Grade 1 Water Cycle Lesson — Grade 1 Science

Name: ____________________________ Date: ______________

Student Handout

Room 2 at Milburn School packed snow into two clear cups. They marked the snow line in each cup. Then they let the snow melt and marked the water line. They measured every line with cubes.

Cup	Snow line	Water line
Cup 1	9 cubes	3 cubes
Cup 2	8 cubes	2 cubes

How many cubes tall was the snow line in Cup 1?
How many cubes tall was the water line in Cup 1?
How many cubes did the line drop in Cup 1?
How many cubes did the line drop in Cup 2?
Add the two snow lines. How many cubes is that in all?
The snow lines were much taller than the water lines. Tell why you think that happened.
Write one sentence. Tell where the water goes when the snow on the school field melts.

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

Answer Key

Answer: 9 cubes.
The chart lists Cup 1 with a snow line of 9 cubes.
Answer: 3 cubes.
The chart lists Cup 1 with a water line of 3 cubes.
Answer: 6 cubes.
The snow line stood at 9 cubes and the water line at 3 cubes, and 9 minus 3 is 6.
Answer: 6 cubes.
Cup 2 dropped from a snow line of 8 cubes to a water line of 2 cubes, and 8 minus 2 is 6.
Answer: 17 cubes.
Adding the 9-cube snow line in Cup 1 and the 8-cube snow line in Cup 2 gives 17 cubes.
Answer: Accept any answer naming air in the snow.
Sample response: snow is full of tiny air spaces between the flakes, and when it melts the air leaves, so only the water is left and it takes up much less room.
Answer: Accept any reasonable path.
Sample response: the melted snow soaks into the ground or runs down the ditch into the creek, and some of it goes back up into the air later.

Differentiation

Support

Pre-build a cube tower for each group and mark it in fives so students count on from a known point rather than counting every cube from one. For item 3 and item 4, give students the two cube towers themselves and let them lay one beside the other and count the leftover cubes instead of subtracting on paper.

Extension

Have groups pack one cup with loose fluffy snow and a second cup with snow pressed down hard, measure both, and compare the drops. The pressed cup loses fewer cubes, which lets students argue from their own data that the air between the flakes is what disappears rather than the water itself.

ELL supports

Pre-teach "snow," "melt," "cube," and "line" by pointing to each one on the demonstration cup as it is named, and post a two-picture card showing a cup of snow beside a cup of melted water. Allow items 6 and 7 to be answered by drawing the before-and-after cups with an arrow between them, labeled with a single word each.

Extensions

Set one measured cup of snow in a warm spot and an identical cup in the coldest corner of the room, then measure both water lines at the end of the day. The two cups reach the same water line eventually, which shows students that warmth changes how fast the snow melts without changing how much water was stored in it.