Classroom activity Grade 2 Engineering & Design

Wheelhouse Street's Straw Pipeline Build Challenge

A 40-minute grade 2 team challenge in which groups estimate, join, and measure straw pipelines to carry water 30 inches from a model tank to a house cup.

Grade: Grade 2
Subject: Engineering & Design
Material: Classroom activity
Time: 40 min
Prep: Moderate prep
Materials: 6 plastic drinking straws per team, each about 8 inches long, Masking tape, about 5 pieces per team, 2 plastic cups per team, one for the tank and one for the house, with a straw-sized hole near the bottom of the tank cup, A stack of 2 books per team to raise the tank, A long shallow tray per team, or two baking sheets end to end, to span 30 inches, Rulers marked in inches, A pitcher of water and paper towels

Standards

K-2-ETS1-2 NGSS

Develop a simple sketch, drawing, or physical model to illustrate how the shape of an object helps it function as needed to solve a given problem.

How this material aligns: Each team sketches its pipeline before building and labels how the downhill slope and the joined straw shape carry water from the tank to the house.

All materials for K-2-ETS1-2 →

2.MD.A.3 Common Core Math

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

How this material aligns: Before measuring, every team estimates in inches how long a line of straws must be to reach the house cup, then checks the estimate with a ruler.

All materials for 2.MD.A.3 →

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: Handout items 1 through 5 add and subtract straw and street lengths in inches within 100, all stated in the same unit as this standard requires.

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 2026-07-23.

Objectives

Students will build a straw pipeline that carries water from a raised tank to a house cup.
Students will estimate a pipeline length in inches and then check the estimate with a ruler.
Students will add and subtract lengths within 100 to plan how many straws a pipeline needs.

Vocabulary

Key words: pipeline, joint, slope, estimate, tank

Teacher overview

Teams of three build a working pipeline out of drinking straws to carry water across a model of Wheelhouse Street, from a tank cup raised on two books to a house cup 30 inches away. A straw pipeline like this one needs every joint sealed and the house end lower than the water in the tank, so a line with a loose joint leaks water before it reaches the house. Finding and fixing leaking joints is also work a distribution crew does on a real main. The six-straw limit requires teams to plan before they build. Run this over a tray or outdoors, and treat a failed first round as expected, since the rebuild in step 6 is where teams apply what the first test showed them.

Activity Directions

Set up each station (before class). Place a tray on a table. An adult pokes a straw-sized hole near the bottom of each tank cup. At one end of the tray, stack two books and set the tank cup on top. At the other end, mark a spot 30 inches away and set the house cup there. Lay out 6 straws, 5 pieces of tape, and one ruler per team.
Introduce the problem (5 min). Read aloud: "Water sits in the tank at the top of Wheelhouse Street. The houses are down the street. There are no pipes yet. Your team will build the pipe." Point out the two rules: only 6 straws, and the water may not be carried by hand.
Estimate first (5 min). Each team writes down how many straws it thinks the line will need and how many inches long that line will be. Collect the estimates before any building starts, so that no team revises its number after seeing how the build goes.
Sketch the pipeline (5 min). Every team draws its plan from the side, marking the tank, the house cup, and the slope of the line with an arrow. Check each sketch for the arrow before releasing tape to that team.
Round 1 build and test (10 min). Teams tape their straws end to end, push one end into the hole in the tank cup, run the line to the house cup, and pour half a cup of water into the tank. They record one word for the result: reached, stopped, or leaked.
Round 2 rebuild (8 min). Teams fix one thing and test again. Common fixes are taping the joints all the way around, raising the tank end, and shortening the line so it does not sag in the middle. Every team gets exactly one rebuild, which keeps the round short and forces a choice.
Measure and record (4 min). Teams measure their finished line with the ruler and compare the measurement with the estimate they wrote in step 3. Teams that reached the house cup post their line length on the board.
Debrief (3 min). Ask two questions and take three answers each: "What made water stop in the middle of a line?" and "Why did the tank have to sit higher than the house?" End when both questions have been answered with a reason, not only a description.

Wheelhouse Street's Straw Pipeline Build Challenge — Grade 2 Engineering & Design

Name: ____________________________ Date: ______________

Student Handout

Read each problem. Show your work. Write the unit.

Each straw is 8 inches long. Team Red taped 2 straws end to end. How long is that line?
Team Blue taped 3 straws end to end. Each straw is 8 inches long. How long is that line?
The house cup sits 30 inches from the tank. Team Blue's line is 24 inches long. How many more inches of line does Team Blue need?
Team Red's line is 16 inches long. Team Blue's line is 24 inches long. How much longer is Team Blue's line?
Team Gold's line is 32 inches long. The house cup is 30 inches away. How many inches too long is Team Gold's line?
Team Red used 2 straws. Team Blue used 3 straws. Team Gold used 4 straws. How many straws did the three teams use in all?

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: 16 inches. Add the two straws: 8 + 8 = 16.
Answer: 24 inches. Add the three straws: 8 + 8 = 16, and 16 + 8 = 24.
Answer: 6 inches. Subtract the line length from the distance: 30 - 24 = 6.
Answer: 8 inches. Subtract the shorter line from the longer line: 24 - 16 = 8.
Answer: 2 inches. Subtract the distance from the line length: 32 - 30 = 2.
Answer: 9 straws. Add the three teams: 2 + 3 = 5, and 5 + 4 = 9.

Differentiation

Support

Pre-tape two straws together for these teams so the first joint is already made and the build begins with a working example to copy. Give them a paper strip marked in 8-inch sections for the handout so each straw length can be counted rather than added, and read items 5 and 6 aloud.

Extension

Give these teams a second house cup placed 45 inches from the tank and an 8-straw limit (hand them 2 extra straws), so they must split the line with a taped branch. Ask them to sketch the branch, state how many inches each arm needs, and explain in writing why the far cup fills more slowly.

ELL supports

Pre-teach pipeline, joint, slope, and tank by pointing to each part of a demonstration line built at the front of the room. Provide the frames "Our line is ___ inches long" and "The water stopped because ___," and let teams report results by pointing to the model rather than describing it.

Extensions

Ask the class where the pipes are in the school building and take a short walk to find exposed pipes in a cafeteria or a boiler-room doorway, noting which way each one runs without touching any pipe. Teams can then redraw their Wheelhouse Street plan as a map seen from above and mark where a valve would go to shut off one house without shutting off the rest.