Significant Figures are great – if you know all the rules, and can keep them straight. Honestly, as an adult with a bachelor’s in chemistry, there are times that I find myself struggling with sig figs. In my state, significant figures aren’t REALLY a part of our standards. I mean, they are, but not really, so I struggled for a while coming up with a good significant figures activity. In NY sig figs are sort of introduced in chemistry and really paid attention to in physics, the following year. My kids need to know how to count significant figures, which isn’t too terrible. My chemistry students also need to know the rules for singular calculations. I’ve grappled with how exactly to teach significant figures in chemistry. It’s hard to judge how much time I should spend on it, and how in depth I really need to go.
Significant Figures Practice
In order to teach significant figures, I truly believe kids need practice with it. I typically spend one day teaching how to count significant figures, using the Pacific-Atlantic method. Then we will usually do some whiteboard practice. Most of the kids leave the class with a full understanding of significant figures. The next day, I break a lot of brains.
My students have already learned the difference between accuracy and precision at this point. I teach that when we do the percent error equation. The kids know that calculations and the numbers that we report, all the way down to how we round those numbers is important. My kids have a tendency to really understand WHY we need significant figures, but it’s the HOW that gets them.
So the answer becomes “practice.” But asking a bunch of 15 year olds to do mindless calculations to get their practice is a mission destined for failure. Nobody wants to do that. There’s no practical use for that. In addition, my kids are too new at chemistry to really try to tie these skills into a lab activity. My solution? Turn it into a game. And on top of that, make it a competition.
Significant Figures Activity
We do a Significant Figure Race! I organize the students, using these grouping pencils, into groups of two to four (depending on class size and amount of time). Then I give them a series of very simple math problems that require good attention to the details of significant figures rules. A student answers one question and passes it to the next kid. The first answer becomes part of the second question. I tell the kids that they need to check the work of the kid before them, to make sure that their question is correct. Then the second kid will answer their question and pass to the third in the group. Then the fourth answers the final question and passes back to the first student to check the final answer. I usually have the kids each have a different color pen or pencil so I can identify who wrote each answer. The group of four who answers their question series first, or the most question series (depending on what I choose) wins!
You can grab this epic significant figures activity for your classroom here! It includes 10 unique worksheets for your students to grapple with, and of course, answer keys!
Other Ways to Use This Activity
You could add in elements of students having to work silently. The condition of silence makes the game that much more challenging! I also like allowing groups to use life lines. So they can ask me to remove a wrong answer from their paper, or ask for a verification on a question that may be tough so they can move forward. When the competition is really tough, I’ve even made the life line of pausing another group’s work for 10 seconds. They have to flip their paper over and can’t work for ten seconds so other groups can speed past them. I’ve done this more quietly as a gallery walk as well. It’s not so much my style, but it could certainly work with kids that are a bit more timid.
Make Boring Skill Drills More Fun
This activity turns something SUPER BORING into something fun – especially if you can award a prize to the winning group (I suggest candy or stickers). You may find that a common theme in my classroom is to trick my students into learning by changing worksheets into games. I do that quite a bit and the reason I’m able to plan all of these fun activities is because my curriculum is squared away. I went through the All Star Planning process and I have never looked back. You can learn more about the other games I play in my classroom here.
