3rd grade engineering activities

The balloon car rebuilt so 3rd graders run fair tests and find failure points, five more design challenges, a free printable, and every 3rd grade engineering Mission by standard.

  • By Skyler Carr, co-founder and CEO, Mission.io
  • Last updated

Who we are. Mission.io makes Missions: teacher-led, whole-class simulations where students use what they’re learning to work through a real scenario together.

Everything on this page works without us. Every 3rd grade engineering Mission is at the end, by standard, free. (Tsunami gives your class three islands, one wave, and a defense to redesign on each. The wave doesn’t take requests.)

On this page

What 3rd grade engineering looks like

Third grade engineering activities are design challenges where the class defines a problem with criteria, builds more than one way to solve it, and runs fair tests to find what to improve, with each student answerable for a piece. This page covers the 3 to 5 engineering design standards, 3-5-ETS1-1 to 3-5-ETS1-3, with a challenge and a Mission for each. The 3rd grade science activities page carries the investigations.

Third grade is the first year of the 3 to 5 band, and the band asks for three moves. Define a design problem with criteria for success and constraints on materials, time, or cost (3-5-ETS1-1). Generate and compare more than one solution against those criteria (3-5-ETS1-2). Then run fair tests, with the variables controlled and the failure points found, to decide what to improve (3-5-ETS1-3). Third grade’s own design tasks come from the science: a problem solved with magnets (3-PS2-4), and a claim about a design that reduces the damage from a weather hazard (3-ESS3-1). The first forces standard (3-PS2-1) is what the balloon car applies.

You know the activity that usually stands in for all of that. It’s a drag race: a water bottle on bottle-cap wheels, a balloon taped to a straw, and a cheer for whichever car rolls farthest down the hallway. Ask for the same result three runs in a row, and the class has to engineer it.

Six things that turn a build into engineering

The standards set the bar on purpose: NGSS raised engineering design “to the same level as scientific inquiry,” and at grades 3 to 5 that means defining the problem with criteria and constraints, researching more than one solution, and revising (NGSS Appendix I). The catch is the clock. Engineering is written into the science standards, so it shares science’s time, and grades 3 to 5 average about 23 minutes a day on science (2018 NSSME+). A build that eats three of those days had better be engineering.

  1. 1. A real problem with stakes the class can feel.

    “Farthest wins” is a race. “The clinic needs its medicine, and it can’t count on luck” is a problem.

  2. 2. Apply, don't recall.

    A second round that only works with the numbers from the first three runs. If the car can be finished without testing anything, it isn’t engineering.

  3. 3. Group goals with individual accountability.

    The one most build challenges miss: the kid who can thread a skewer builds the car, and three kids wait for the hallway. When the group shared a goal and each student answered for a part, 84% of studies found a positive effect; without both, 17% (Slavin, 1991).

  4. 4. The teacher leads the thinking.

    Ask three questions at the launch line: what’s your variable, what failed and which force did it, what are you keeping the same. Those teach more than the finish line ever will.

  5. 5. A debrief where the class argues it out.

    The build is the setup. The argument afterward, about which change got cars to the clinic and which one made them veer, is the practice the standards name.

  6. 6. A way to see who did what.

    If you can’t tell which student called the change and which one only blew up the balloon, you can’t teach the design process. You can only measure the hallway.

Change two things at once? The car won’t say which worked.

The printable at the end of the next section puts all six on the launch line, with every card and log the activity uses, ready to copy. Get the sheet →

The balloon car, rebuilt for 3rd grade (3-5-ETS1-3)

A car body (a bottle, cardboard, or a cup) on bottle-cap or CD wheels with skewer axles, driven by air escaping from a balloon through a straw, and tested for distance. It’s on STEM lists from 3rd grade through 8th, and third grade is where it starts, because 3-PS2-1 is the first forces standard and the balloon is the first visible push. The way it usually runs is one builder, a hallway, and “farthest wins.” Here’s the version that hits all six.

Time
60 minutes; the wheels take time. The 45-minute cut: pre-assemble the axles and wheels on the body the day before (or use a kit chassis), so the lesson is balloon, straw, and testing, and keep the debrief.
Groups
Fours. With 25 students, six groups of four and one of three, where the Measurer also records.
Supplies for seven cars
7 small water bottles or cardboard rectangles, 28 bottle caps or CDs, 14 skewers, 14 straws, 14 balloons, tape, and meter sticks. About $12 if the caps are collected.
Standards
3-5-ETS1-3 (fair tests, controlled variables, failure points), applying 3-PS2-1 (balanced and unbalanced forces change an object’s motion). The forces are the content; the car assesses the engineering.

  1. Teach first, 10 minutesApply

    Blow up a balloon and let it go across the room. Then hold a balloon on the desk with the neck pinched and ask what will happen when you let go, and why. Name it: the air pushes out one way, and the balloon moves the other; an unbalanced push changes motion. Then name the three things a car builder can change: balloon size (how many breaths), wheel alignment, and car mass.

  2. The problemStakes

    A rescue cart has to carry a medicine bottle (a cap taped on as cargo) from the launch line to the clinic, taped 3 meters away, without a push, and it has to get there three times in a row because the clinic can’t count on luck. The criteria: the cargo arrives in the clinic zone on three of three runs. The constraints: one balloon, one straw, the body and wheels on the tray, and 10 minutes per build round.

  3. Four roles, one job eachAccountability

    On the sheet, and every student signs their role’s box. Builder and Inflator swap between rounds.

    • Builder

      The only hands on the car body and the wheels.

    • Inflator

      The same number of breaths every run, counted aloud.

    • Measurer

      Reads the stopping point to the nearest 10 cm.

    • Recorder

      Three runs per round, the one variable changed, and a where-it-failed note: veered, stalled, or cargo fell.

  4. You lead the thinkingTeacher leads

    Three questions, asked at the launch line: What is your variable this round? What failed on the last run, and what force do you think did it? What are you keeping the same?

  5. Two rounds, so the test has to be usedApply

    Build and run three times, then 3 minutes to change one variable, then three more runs. The second round only says something if the Inflator kept the breaths the same.

  6. The debrief, 10 minutesDebrief

    Every team’s six distances on a class chart. Which change got cars to the clinic three times, and which change made them veer? What push moved your car, and what slowed it down? Who in your group called the change that worked? The second question is balanced and unbalanced forces in one sentence.

  7. See who did whatSee who did what

    The observation sheet, four behaviors per student: proposed a change with a reason, kept a variable the same on purpose, disagreed with a reason, changed their mind with a reason. A tally catches about half the room; the hallway lane means teams waiting their turn, and that’s when you tally.

(Expect a ruling on whether a breath counts if somebody laughed during it. That’s the Inflator’s call, and it’s a controlled variable.)

Save the class chart with its failure column. Reactor Revamp asks for the same thinking, on a fusion reactor.

The rescue cart balloon car, free

Emailed now, ready to copy: the teacher page, four role cards, one team log (the criteria and constraints, round 1’s three runs, the variable changed, and round 2’s three runs), and the four-behavior tally.

It’s on its way.

Check your inbox for the rescue cart balloon car.

Email me the sheet. It comes as a PDF, ready to print. Unsubscribe anytime.

Five more 3rd grade design challenges, by standard

Five more on every 3rd grade list: what each one is, how it usually runs, and what it needs to be engineering, in the order the standards run.

Define, compare, test

2. The pulley that lifts a load (3-5-ETS1-1)

Needs a spool, string, a cup of washers.

Students run a string over a spool and pull to lift a cup of washers. The force idea gets used right away, because they can feel how the pulley changes the pull. As usually run, though, it’s a demo of “it’s easier,” with nothing to aim for, and one student does the pulling while the rest watch.

The fix

  1. Set a load target, like a set number of washers lifted to the top of a stack of books.
  2. Give three jobs: a Puller, a Loader who adds the washers, and a Recorder who writes what each try lifted.
  3. Compare the setups that hit the target, and ask the Pullers what they felt change.

No page for this one; the load target and the three roles are the fix.

3. The straw roller coaster for a ping-pong ball (3-5-ETS1-2)

Needs straws, tape, a ping-pong ball.

Teams tape straws into a track that carries a ping-pong ball from start to finish, often into a cup at the end. Every hill and turn puts the forces unit to work. As usually run, though, it’s a build with no test criterion, so any ball that reaches the end counts, and there’s no record of what changed between tries.

The fix

  1. Make a time target the criterion: the ball has to reach the end within a set time.
  2. Use four roles on the catapult’s pattern: a Builder, a Releaser, a Timer, and a Recorder.
  3. Log the time for every run, so the team can see what each change did.

See it fixed on the 3rd grade STEM page →

4. The craft stick catapult (3-5-ETS1-3)

Needs craft sticks, rubber bands, a plastic spoon, pom-poms. Fours.

Students rubber-band craft sticks around a plastic spoon and launch pom-poms across the room. It’s a third grade favorite, with a force in every launch. As usually run, though, it’s a contest for distance, nothing rides on where the pom-pom lands, and the team can’t say what made one launch better than another.

The fix

  1. Turn it into a supply drop: a pom-pom crate has to land in a taped square three launches in a row.
  2. Give four roles, such as a Launcher who pulls back to the same mark every time and a Measurer who reads each landing.
  3. Change one variable between sets, and compare the landings before and after.

See it fixed on the 3rd grade STEM page →

5. The index card bridge, longer span (3-5-ETS1-3)

Needs index cards, straws, masking tape, pennies, books as piers.

Teams fold index cards and tape straws into a bridge between two books, then load pennies until it sags or falls. In third grade the span gets longer, and the penny count is a real result. As usually run, though, a couple of students build while the rest drop pennies, and no one can say who did what.

The fix

  1. Give four roles: a Folder, a Taper who says why the tape goes there, a Loader, and a Recorder who draws the bridge before each test.
  2. Run two rounds, and have the Recorder write the load each version held, so the team compares two tested bridges.
  3. Swap the Folder and the Loader between rounds, so nobody owns the bridge.

See the index card bridge rebuilt for 2nd grade →

6. The magnet latch or magnet crane (3-PS2-4)

Needs magnets, building materials.

Students design something that uses magnets to solve a problem, like a latch that keeps a cabinet door shut or a crane that picks up paper clips. It already has a real problem and uses the magnet science from the unit. As usually run, though, it stays a drawing, so the design never meets a test, and there’s no way to see what each student did.

The fix

  1. Have each team build its latch or crane from the materials on the tray.
  2. Test every design the same way: how many clips the crane lifts, or whether the latch holds when the door is pulled.
  3. Have each student record one test result and say what they’d change next.

No page for this one; building and testing it is the fix.

  • Our part · We make Missions

    Then the unit has somewhere to go

    Plenty of teachers rebuild these by hand every unit, and it works. A Mission is a teacher-led, whole-class simulation built from a unit you teach. The balloon car is fair testing (3-5-ETS1-3), and Tsunami, below, is built to the band’s first two codes. Reactor Revamp carries the car’s own standard, on a damaged fusion reactor. After the balloon car, run Reactor Revamp.

    You're at the helm, not on the hook.

    Tsunami: the design unit, as a Mission

    Tsunami · 3rd grade · About 43 minutes · One device per student, plus your projector · Free with a teacher account

    A smiling teacher looks down at a group of elementary students gathered in front of her, with paper handprints and drawings on the wall behind.
    A teacher grinning down at a huddle of students.

    A deep-ocean earthquake has set off a massive tsunami on Viper I, and three populated islands are in its path. The crew has to design an improvement to each island’s own defense system, based on what that city and that island need. The story plays on the projector. The work happens at seven stations (Command, Engineering, Medical, Security, Science, I.T., Operations) and in the arguments between them.

    Every student is assigned to a team, and each team’s work is themed to it, from its own information and challenge to the same problem the rest of the crew is solving. The team gives a student a role in the story and people to lean on while you move between teams, asking what this island needs protected most, which design meets that, and what it gives up.

    It’s built to the band’s first two codes (3-5-ETS1-1 and 3-5-ETS1-2) and to 3rd grade’s weather hazard standard (3-ESS3-1), and the vocabulary is the unit’s: tsunami, solution, evidence, criteria, design. Run it when your weather hazards unit is ready. No island gets saved by a crew that can’t say what counts as saved. The lesson prepares them. The Mission is what they’re preparing for.

    “My students ask every time they walk in the door, ‘IS IT A MISSION DAY?’”

    Kate Fallon, Teacher, St. Amelia School, NY

    Will it work in my room?

    Students join with a class code: no student accounts, no student email, no passwords. Chromebooks, laptops, or tablets, plus your projector. Free for teachers, no credit card. Student data is covered by COPPA and FERPA, and we signed the Student Privacy Pledge. At about 43 minutes, Tsunami runs 20 minutes past the average 3 to 5 science block. Give it a full period.

    START FREE →

    Communication first, then the unit's two

    What the report shows

    A Mission.io class report: the class score in each of six skills, from knowledge and application to collaboration, critical thinking, and resilience, with the class chart across the year below.
    A class report from a real Mission: the class score in each of six skills, then each skill across the year.

    Every Mission produces a report for every student, built from what that student did across the whole Mission, on the skills the Mission captured. The six it can capture are Knowledge, Application, Initiative, Collaboration, Critical Thinking, and Resilience. The first two are what a test already sees. The other four are the human skills every school promises. The test shows what they know. The report shows the rest. SEE THE EVIDENCE →

    You taught it. Now find out who can use it.

    Who's behind it

    Mission.io is a research and design organization with one job: make collaborative, active learning something a teacher can run every unit instead of once a semester, and put a report in your hands when it’s over. Over a million students have run a Mission. The research behind them is funded by the National Science Foundation and the U.S. Department of Education’s Institute of Education Sciences, and Mission.io meets ESSA Level II standards, as validated by Instructure.

    3rd grade engineering Missions by NGSS standard

    Tsunami is one. There are 3 engineering Missions at 3rd grade, numbered 7 to 9 below, all three built to the 3 to 5 engineering design standards. Each code links to its standard on nextgenscience.org.

    Engineering design (3-5-ETS1)

    Each of the band’s three moves has a Mission. At 17 minutes, Engineering Solutions is the only one that fits inside a 23-minute block.

    Engineering design Missions for 3rd grade, by NGSS code.
    NumberThe standardMissionMinutes
    73-5-ETS1-1, 3-5-ETS1-2, 3-ESS3-1 Define each island’s problem, compare defense designs against its criteria and constraints, and argue for the one that reduces a weather hazard (3rd grade). On this page: 2. The pulley and 3. The roller coaster.Tsunami43
    84-ESS3-2, 3-ESS3-1, 3-5-ETS1-1, 3-5-ETS1-2, MS-ETS1-2 Compare wave barriers that reduce the damage from a tsunami before it reaches the city (grades 3 to 5). On this page: 2. The pulley and 3. The roller coaster.Engineering Solutions17
    93-5-ETS1-3 Fair tests and failure points: improve a prototype from the data (grades 3 to 6). On this page: 1. The balloon car, 4. The catapult, and 5. The index card bridge.Reactor Revamp45
    START FREEMISSION BRIEF →

    Free teacher account, no card. Start with the Communication Mission, marked Start here in your library, then Tsunami or Reactor Revamp, each after its 5-minute Teacher Preview.

    Also at this grade

    The 3rd grade science activities page maps 16 science and engineering Missions by NGSS code, these three among them, and rebuilds magnet strength; the 3rd grade STEM activities page rebuilds the craft stick catapult; and for math, see 3rd grade math activities.

Questions 3rd grade engineering teachers ask

I get 23 minutes for science in 3rd grade. Where does engineering fit?

Engineering Solutions fits, at 17 minutes. Tsunami runs 43, 20 minutes past the block, and Reactor Revamp runs 45, which fills the whole 45-minute period, with no time left for the debrief. The balloon car takes 60 minutes, or 45 with the axles and wheels pre-assembled the day before.

Which 3rd grade engineering standards does this page map?

The three 3 to 5 design standards, in the band’s first year: 3-5-ETS1-1 (define the problem), 3-5-ETS1-2 (compare solutions), and 3-5-ETS1-3 (fair tests and failure points). Each has a Mission and a challenge on this page. Third grade’s own design tasks are here too: the magnet problem (3-PS2-4) in 6. The magnet latch, and the weather hazard (3-ESS3-1) in Tsunami.

Why does the 3rd grade balloon car lead to Reactor Revamp, and not Tsunami?

The car and Reactor Revamp share a code: fair tests and failure points (3-5-ETS1-3). Tsunami is built to defining the problem and comparing solutions (3-5-ETS1-1 and 3-5-ETS1-2), with 3rd grade’s weather hazard standard, so it belongs at the end of a weather hazards unit.

Is a balloon car too hard for 3rd graders?

The build can be, which is why the 45-minute cut pre-assembles the axles and wheels. With the chassis done, the lesson is balloon, straw, and testing, and the Inflator counting breaths out loud is how third graders hold a variable steady.

Do 3rd grade engineering Missions match my state's standards, not just NGSS?

Each Mission page lists the state sets it maps to. Tsunami maps to 22 state science sets, Alabama’s through Wyoming’s. Reactor Revamp maps to 14, two of them ELA sets, because it also carries reading and speaking codes.

3rd grade engineering that gets the medicine to the clinic

Day one, a challenge by hand with the sheet. Day two, Reactor Revamp after the balloon car, with its 5-minute Teacher Preview. Both free.

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