In my experience as a chemistry teacher, I’ve found my students often struggle with math skills. And this has made my job tougher, considering my chemistry classes are algebra based. Luckily for them, I was also not so good at math. And I feel like that puts me in a good place to help my students. In this post, I’m talking about how I help my students to understand weighted average and average atomic mass.
Relate it to grades and report cards
Taking an average is an elementary math skill. By the time your students get to you, they should have a pretty good understanding of regular averages. So in my average atomic mass activity, students use what they already know about averages and learn a bit more.
The idea is that a student is asked to help their teachers to finalize grades for the report card because the grading system went down.
Practice with Traditional Unweighted Averages
The first task is to determine the test average, quiz average and classwork average for one of the teachers who is behind on grading. This gives the students a chance to do a traditional unweighted average. In each category, each component is weighted equally, so this task is review for students.
Move into Weighted Averages
Then the students have to determine what the class averages are. This is going to be different in each class based on how the teachers give weight to each category in their class. Each of the teachers have 3 categories with varying weights. It’s a simple way to connect weighted averages to average atomic mass.
Finally the activity ends with a few chemistry average atomic mass questions for some elements with a few isotopes each.
When to Use this Activity
The concept of isotopes and average atomic mass goes on for about a week in my classroom. Students begin by learning about isotopes. I teach one of my guided notes lessons on isotopes and the following day we do an escape room activity. (I’m working on getting this up on TPT eventually…) Then on the third day I teach them average atomic mass. If time allows we would do this activity on the same day, if not, on the fourth day. Then to finish off the school week, we do the average atomic mass of cadmium lab activity.
You can check out the lessons and labs in my topic bundle on Teachers Pay Teachers.
I’ll say, the report cards are an amazing real life application! It’s great to help students to understand weighted average and average atomic mass.
