Lesson plan Grade 2 Math

Estimating and Measuring Stonewell's Water Main: A Grade 2 Lesson

A 40-minute grade 2 lesson where students estimate, then measure with a yardstick, three taped pipe sections from Stonewell's water main, and add the lengths.

Grade: Grade 2
Subject: Math
Material: Lesson plan
Time: 40 min
Prep: Low prep
Materials: Masking tape, Yardsticks (one per group), Recording sheet with estimate and actual columns, Index cards, Picture of a water tower for Stonewell (a fictional town used for this lesson)

Standards

2.MD.A.3 Common Core Math

Estimate lengths using units of inches, feet, centimeters, and meters.

How this material aligns: Students estimate the length in feet of each of three taped pipe sections representing Stonewell's water main before measuring them, the estimating-in-feet task this standard requires.

All materials for 2.MD.A.3 →

2.MD.A.1 Common Core Math

Measure the length of an object by selecting and using appropriate tools such as rulers, yardsticks, meter sticks, and measuring tapes.

How this material aligns: Students select and use a yardstick to measure each taped pipe section in feet, choosing an appropriate tool exactly as this standard describes for a real-world length.

All materials for 2.MD.A.1 →

2.MD.B.5 Common Core Math

Use addition and subtraction within 100 to solve word problems involving lengths that are given in the same units, e.g., by using drawings (such as drawings of rulers) and equations with a symbol for the unknown number to represent the problem.

How this material aligns: Students add the three measured pipe-section lengths, each given in feet, to find the water main's total length, the same-unit length word problem this standard names.

All materials for 2.MD.B.5 →

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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 estimate the length of a taped line in feet before measuring it.
Students will measure lengths using a yardstick and record the length in feet.
Students will add three measured lengths to find a total pipe length in feet.

Vocabulary

Water main: A big underground pipe that carries drinking water beneath the streets to a neighborhood. Smaller service lines branch off it to reach each building.
Water tower: A water tower is a big tank raised high above town that stores drinking water. Its height is what pushes water through the pipes, keeping the pressure steady even when the power goes out.

Also: estimate, yardstick

Teacher overview

Stonewell (a fictional town used for this lesson) stores its drinking water in a tower that connects to homes through an underground pipe called a water main. This lesson uses three strips of masking tape on the classroom floor, standing in for three sections of that water main, to practice estimating a length before checking it with a real tool. A common misconception in this lesson is that a length can be judged accurately just by looking at it; the estimate-then-measure routine in guided practice corrects that directly by checking every guess against a yardstick.

Students work in small groups to estimate, measure, and record three lengths, then use addition and subtraction to find the water main's total length and compare two of its sections.

Procedure

Minutes 0-5 -- Hook: Show a simple picture of Stonewell's water tower on the wall. Explain that water travels from the tower through underground pipes, joined together in sections, called a water main. Ask students to guess, without measuring, how long one section of pipe might be in feet. Write two or three guesses on the board without comment.

Minutes 5-15 -- Direct instruction: Introduce "estimate" and "yardstick." Tape a demonstration line on the floor, have the class estimate its length together, then measure it with a yardstick to check. Model recording both the estimate and the actual measurement on a recording sheet with two columns.

Minutes 15-30 -- Guided practice: In groups, students estimate the length of Segment A (a taped line on the floor) in feet and record their guess. They then measure Segment A with a yardstick and record the actual length: 5 feet. Repeat as a class for Segment B (8 feet) and Segment C (4 feet), discussing why a yardstick, not a bathroom scale, is the right tool for this job.

Minutes 30-37 -- Independent practice: Each student solves these two problems using the three actual measurements (5 feet, 8 feet, and 4 feet):

What is the total length of the three pipe sections joined end to end?
How many feet longer is Segment B than Segment C?

Minutes 37-40 -- Closure / exit ticket: Students answer one question on an index card: "A new fourth pipe segment measures 6 feet. If it is joined to the first three, what is the new total length?" Collect and check for the correct method (adding 6 to the earlier total) before dismissal.

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: 17 feet. 5 + 8 + 4 = 17 feet.
Answer: 4 feet. 8 minus 4 equals 4 feet.
Exit ticket answer: 23 feet. The earlier total of 17 feet plus the new 6-foot segment equals 23 feet.

Differentiation

Support

Give groups a yardstick already lined up next to Segment A with the first foot marked, and allow students to round their estimate to the nearest foot instead of expecting an exact number.

Extension

Ask students to tape a fourth segment of their own choosing, estimate it, measure it, and figure out the new grand total for all four segments without re-adding the first three from scratch.

ELL supports

Pre-teach "estimate," "yardstick," and "water main" with a hand gesture (holding hands apart to show a guessed length) before measuring. Provide a sentence starter for the recording sheet: "I estimate the pipe is about ___ feet long."

Extensions

Invite a distribution-system operator or public works staff member to explain, in a short visit or a video call, how workers measure real pipe sections before installing them underground.