How to Make Labs Run Smoothly (Even in Large Classes)
Science labs are one of the best parts of teaching. Watching students make connections, test ideas, and get excited about “real” science. But if you’ve ever tried running a lab with 30+ students in one room, you know it can feel more like crowd control than hands-on learning.
Let me hear one comment about too many posters on the wall being a fire hazard — insert eyeroll here —, while we have over 30 kids trying to practice lab safety and learn something!
The good news? You can keep labs engaging and organized even in your biggest classes with a few simple tricks up your sleeve.
Quick Win #1: Set Clear Roles
One of the fastest ways to cut down on chaos is to assign specific roles to each lab group. Instead of everyone crowding around one beaker, students know exactly what they’re responsible for.
Try roles like:
Materials Manager – gathers and returns supplies
Recorder – writes down data and observations
Timekeeper – keeps the group moving on schedule
Reporter – shares results during class discussion
Rotate roles within the lab group so that everyone gets the opportunity to play each part.
👉 Action Step: Write the roles on your lab instructions so students see them right away and have them write their names next to their role. This keeps groups balanced and prevents the “one kid does it all” syndrome.
Quick Win #2: Use Station Setups
If your class size makes labs feel overwhelming, stations are your best friend. Instead of 30 students jostling for materials at once, set up lab stations around the room. Groups rotate through, and each station has everything they need in one spot.
Not only does this cut down on traffic jams, but it also helps with classroom management—students know exactly where to go and what to do.
👉 Action Step: Keep a bin or tray for each station stocked with the full set of supplies. You can reset quickly between classes without hunting down missing materials.
Quick Win #3: Break Up the Class
One of the simplest ways to manage a big group is to split the class in half. Instead of trying to run the lab with 30+ students at once, let one side of the room conduct the lab while the other side works on a lab-related practice activity (data analysis, reading assignment, or guided questions). Make that lab-related practice count toward their overall lab grade for the day.
After a set time, switch. The second group gets their turn at the lab while the first group works on the practice task.
This setup not only reduces crowding at lab tables but also gives you more room to circulate and support students as they work. Everyone still completes both parts of the assignment; they just do them in staggered sessions.
👉 Action Step: Look at your next lab and ask, Could I split this in half? Choose a simple practice task for one group while the other runs the lab, then rotate.
Save Even More Time with Ready-to-Use Labs
So teacher life has a way of teacher lifing at all the wrong moments. Even with the best systems and tricks up your sleeves, something will always come up, you’ll always need a pivot option, and you’ll for sure always learn new and improved ways to execute with your unique class.
And while I can’t help you bob and weave to avoid all of those teacher life moments, I can help with the lab activity itself and additional on-topic resources.
And if you’re tired of reinventing the wheel every unit, that’s exactly where SciAcademy comes in. It’s a library of ready-to-use physics and chemistry lessons, labs, and sub plans—all designed to run smoothly, even in large classes.
👉 Want more? Join SciAcademy and get instant access to a full library of no-prep labs and resources.
Final Thoughts
Lab days don’t have to feel like chaos — or a fire hazard waiting to happen. With clear group roles, organized stations, and even splitting the class into rotations, you can keep students engaged and learning, no matter the class size.
Start small: assign roles from the Lab Roles Card set (go ahead and just download it), try a station setup, or run a half-class rotation. Once you see how much smoother lab days can be, you’ll never go back.
⬇️ Download the Lab Roles Card set freebie and get started today. ⬇️
Labs are where science comes alive, and they don’t have to come with the stress and chaos. With a little structure—whether it’s assigning clear roles, setting up stations, or breaking the class into rotations—you can give your students the hands-on experiences they love while still keeping the room under control.
Have fun with labs, enjoy watching your students discover, and know that with the right systems in place, you can keep them focused and learning every single time.
