You’ve spent days teaching significant figures rules. You wrote examples. Students worked problems. Now, the last student has handed in their quiz. You take them home that night to grade and it’s unbelievable.
The zeros are everywhere. They got So. Many. Wrong.
Now there is red all over their papers. And it’s not from your grading assistant, Mr. Cabernet Sauvignon.
What happened? Why can students never remember significant figure rules?
Is it because you are skipping the one step that makes all the difference? After all, no one told you which steps of each lesson are the most important.
Teach Students to Define Zero Types with Specifics
If you are looking for how to teach significant figures, first, define and state the significance of each type of zero for your students. Define the types of zeros as clearly as you possibly can. Here is a straightforward way explain them to students:
Sandwich Zeros- Significant. This phrase brings a sandwich mental image up which makes it more memorable to constantly hungry students. Show that it is a zero between two regular numbers. (This is not math class so maybe don’t scare them with the word non-zero.)
Trailing Zeros with a Decimal - Significant. Tell students these zeros are significant since they show the number was measured to a very specific degree.
Trailing Zeros without a Decimal - Insignificant. Explain to students that this is because they could be rounded or “ball parked" numbers.
Leading Zeros- Insignificant. These are just place holders and don’t contribute to how specific a number is. Tell students that leading zeros will lead you on and make you think they are important, but they aren’t.
Like that boy they are currently dating.
Teach Students to Label Zeros Before Deciding Sig Figs
Here’s the step that many teachers miss because they do this in their head without even thinking. When you are doing the example problems and when students are practicing with you, you must label each type of zero in the problem.
Many of us put a problem up and then ask, “How many significant figures is that?”. Since we’ve just gone over the lesson, they respond correctly. Then, we move to the next example.
But when we are deciding how to teach significant figures, we need to be sure to label each type of zero in the example. That’s the critical missing step that solidifies this idea in students’ minds. Put practice problems on the board, or use one of my worksheets, and have students label each zero in each problem before they decide how many significant figures are there.
After making this change, you will ask your students, “How many significant figures is that?”. They will respond correctly, but this time you will respond to the students by saying, “Yes. Why? Which zeros in this problem were leading, trailing with a decimal, trailing without a decimal, or sandwiched?”
Not only will this reinforce the correct answer to your students, but it will help the students who didn’t know the answer.
When you teach this way, you’ll notice why students make mistakes. It's because they’re mislabeling zeros, which leads to the wrong number of significant figures.
Teach Students to Color Code Sig Figs
Take this idea one step further and color code significant figures. Color coding helps your students who understood the concept today, remember the concept tomorrow.
For example, have students color all significant zeros red. Students love this because they can go through their paper and immediately identify the red zeros as significant when reviewing.
As with my other color coding lessons, you can use any color coding scheme you like as long as it makes sense to you and your students. You can even leave the color coding design up to your students.
Now imagine you’ve spent a few days teaching significant figures rules. You’ve defined, labeled, and color coded zeros along with your students. Students worked problems and really worked at identifying the zero types before determining the number of significant figures.
Now, the last student has just handed in their quiz. You finish grading them as they work on a post quiz activity.
They got it.
Sure, there was a few here and there that didn’t grasp the concept. But, they weren't mixing everything up! Confusion doesn't live in your classroom because you are good at teaching chemistry.
Clearly, you and the students both nailed this lesson.
Want the Worksheets that Make Teaching this Easy?
Significant Figure Doodle Notes- Use the memorable visual illustrations in this worksheet set to help your students take notes, work problems, and learn significant figures in a way they won't forget.
Significant Figure Step by Step Worksheet- Use this worksheet to show students the different types of zeros which will lead to more student understanding than ever before.
Hi! I'm CoScine. I write chemistry worksheets for visual learners. They are fun, easy to follow, and most of them are quick to grade. Since I started my teaching career at the college level, these aren't just simple chemistry. These worksheets are hard core science made fun.