Science Skills: The Metric System

Why do we continue to have to re-teach the metric system to our students every year?  I wish I knew the answer to this question!!  Students are exposed to and taught the metric system beginning in elementary grades, but they still need a refresher on it when they reach my high school chemistry class.  Why is this?  The reason is because a science class is the ONLY place that our students use the metric system.  While they may see references to it here and there, they never really use the metric system in their everyday lives.  Our students understand how many miles it is to the movie theater, but if you asked them how many kilometers to the movie theater, they will stare at you with a blank look.

In 1975, President Gerald Ford signed into law "H.R. 8674: Metric Conversion Act."  This law declared the metric system "the preferred system of weights and measures for United States trade and commerce." This law is ineffectual since it "permits the use of customary units in all activities."  Further, "all conversion was to be completely voluntary."  In other words, we have never converted to the metric system.  Our students haven't mastered the metric system because they do not use it except in our science classes.

Sure, the students know the basics of the metric system.  They know that length is measured in meters, mass is measured in grams and volume is measured in liters, but many of my students are still unsure as to how to convert one unit to another.  It is not unusual at all for one of my students to ask, "Which way do I move the decimal to convert ____ to ____?  Even more confusing is what to do with the units when determining area or volume.  How often have I heard, "Are these units squared or cubed?"

The manipulation of metric units must be reinforced at regular intervals, if for no other reason, than to just reinforce basic math skills.  Here's an example. Multiple the following:  (5 g/ml) (10 mL).  The answer?  50 g.  Many students will struggle when units are being added, subtracted, multiplied or divided. They can multiply 5 x 10, but they do not know what to do with the units.

What are we science teachers to do about this?  We have no choice but to teach, teach, teach! Your science class will go much smoother all year long if you will take a class period (or several!) at the beginning of the year to do a refresher on basic metric skills.

Here are a few resources in my TpT store that might be of some help to you:

Metric System Jeopardy Review Game

Metric System Bundle of 12 products

Metric System PowerPoint

Science Skills Mega Bundle

Metric System Task Cards

FREE Metric System BOOM Cards

Science Skills: Scientific Notation

In this series of blog posts, I have been writing about the importance of teaching "science skills" to our students.  (Previous posts include: Teach the Skills, Graphing Skills are Life Skills, and Applying the Scientific Method.)

The next skill that I would like to discuss is the proper use of scientific notation.  Scientific notation is used to express very small and very large numbers in a manner that makes problem solving easier.  Let's face it, chemistry students cannot enter Avogadro's number in their calculator unless it is in scientific notation.  In biology, viruses and bacteria are measured in nanometers and micrometers.  Both are simple examples of the need to use scientific notation in our science classes.

Many of the students entering my high school biology and chemistry classes are still struggling with how to write numbers in scientific notation.  Why is this?  I don't have the answer.  I worry that we are pushing middle school students to complete Algebra 1 and Geometry too early, and they are not getting the instruction they need in basic mathematics and arithmetic.

Whatever the reason, I find that I must spend a class period each year re-teaching this important skill.  Since my science classes use very large and very small numbers most every day, scientific notation is a must.  My students must be able to:

• Write numbers in scientific notation.
• Change numbers from scientific notion to standard form, and vice versa.
• Add and subtract numbers that are in scientific notation.
• Multiply and divide numbers that are written in scientific notion.

This is a much needed skill in a high school science class.  It is well worth the time to spend a class period reviewing and reinforcing these concepts.

The resources I use in my teaching can be found here:

Scientific Notation PowerPoint, Notes and Worksheet

Science Skills: Applying the Scientific Method

Teaching the “skills of science” is of the utmost importance.   I cannot stress this enough!  Yes, the "content of science" is important, but the content cannot be taught to our students until the skills are taught to our students. Scientific method, metric measurement, scientific notation, prefixes and suffixes, significant figures, compare/contrast, problem solving, critical thinking, dimensional analysis, proper use of lab equipment, scientific writing ... these are the skills I am referring to.  If the skills are taught properly at the beginning of the school year, your students will be equipped with the tools they need to be successful for the rest of the year.  Science is more than the memorization of a long list of facts.  Science is problem solving, analyzing, predicting and experimenting.  Make the teaching of basic science skills a priority in your class.

In a previous article, I talked about the importance of graphing skills.  Today, I want to talk about the importance of being able to apply the scientific method.  The key word here is...... apply.  You may be thinking, "I teach the scientific method every year during the first week of school."  Many teachers have their students write down the 5 or 6 steps to scientific method, define some keywords such as hypothesis, variable, and theory, re-state the 6 steps on a test, and .... DONE!  Time to move on to the next topic.  

We can do better than that.  Teaching our students how to apply the steps of the scientific method is not easy, and it takes up quite a bit of valuable class time.  We have to create lessons that teach the application of the scientific method, not lessons that teach the memorization of the scientific method.  

At the beginning of the school year we should give assignments that:

• Reinforce graphing skills.
• Teach students to interpret and analyze graphs.
• Provide writing prompts to teach students how to design a controlled experiment.
• Teach students to identify the independent and dependent variables in an experiment.
• Teach students how to apply the scientific method to a particular scenario.
• Give students practice in scientific writing.

Please get away from using only multiple choice, true and false, and matching questions.  I try as much as possible to have my students WRITE.  It is very time consuming to grade, but when students are asked "to design an experiment to show..." , you are teaching so many of the above skills.  And you are not just teaching the scientific method.  You are reinforcing critical thinking, problem solving, and best of all, good writing skills.

If you are just beginning to develop lessons on the scientific method, try my Scientific Method PowerPoint.  This is a 26 slide PowerPoint presentation on the nature of science and the scientific method.  The slides are colorful and visually appealing.  Steps of the scientific method are covered, but more importantly, the lesson provides examples and practice problems illustrating the application of the scientific method.  Analysis questions and answers are included.  The download also includes 4 pages of notes for the teacher and a 5 page outline of the notes for the student.  

Now take your students to the lab and see how well they can apply what they have learned about the scientific method.  My "Can Your Students Write a Clear and Concise Procedure" is a great introduction into scientific writing. It's a fun activity that reveals to students the importance of accuracy and details when writing in science.  

Now you are ready to teaching students how to design and carry out a controlled experiment.  Start with this classroom activity (Applying the Scientific Method and Scientific Writing) involving hypothetical situations.  

Forge ahead with a student-designed lab activity:  The Scientific Method Lab. Students will plan and carryout the entire process from start to finish.  Full disclosure ... This takes time and quite a bit of patience, but it is worth it.  Your students will hone their problem solving and critical thinking skills as they complete these activities.

Graphing Skills Are Life Skills!

Graphing: Make this a part of as many lessons as possible!

The lessons learned in a science class go much further than just learning the parts of the cell, or the parts of an atom, or the names of the invertebrate phyla, or the trends seen on the periodic table.  We teach important skills that our students will carry with them for the rest of their lives.  Skills such as graphing, metric measurement, cause and effect, percentages, scientific method, logical problem solving, and critical thinking are required for LIFE!

For this blog post, I would like to focus on graphing skills.  I fear that the use of graphing calculators and laboratory probe systems is doing too much work for our students.  I do love using technology in my classroom and lab, but I think that too much of it is actually hurting our students.  Many students are reaching my high school science classes without a clear understanding of how to construct a graph. We need a healthy balance between allowing technology to do the work for us, and doing the work for ourselves. 

There are so many benefits of giving the student a pencil, a ruler, and a piece of graph paper.  

• Graphing the "old-fashioned" way improves fine motor skills and hand-eye coordination.
• Graph construction forces the student to think about the independent and dependent variables and to consider which axis to place them on to show a logical correlation between the two.
• It provides an excellent opportunity to teach our students to "think ahead of the problem" to consider if an outcome or conclusion is logical. 
• Every standardized test our students take will require them to analyze graphs and tables.  Data analysis is a hard concept for many students, but requiring them to construct their own graphs and tables encourages deeper thinking of the data shown on the graph.
• There is no better way to teach "cause and effect" than by graphing data.
• Graphing provides a pictorial representation of data which helps students learn to draw accurate conclusions.

Obviously, we want students to become masters of problem solving and critical thinking, and teaching graphing skills all year long is one way to assure that our students are good thinkers.  Make your labs and classroom activities "quantitative" in nature whenever possible.  Especially in biology, many activities are "qualitative" and involve drawing and describing, but we need to constantly look for opportunities to use labs and other lessons that are math-based and involve the collection of numerical data. 

• Look at the labs you are currently using with your students. Is it possible to have students graph the data they collect?  If so, then always require it!
• It is really important that students construct graphs that have more than one line of data on the same graph.  By placing several lines of data on the same graph, students can quickly see the correlation between the independent and dependent variables.  It provides excellent practice in how to analyze data to reach a proper conclusion.
• You can provide additional problem solving questions to accompany the graphing activity, such as "What do you suppose would happen if this were changed....", or "What would be the outcome if...."
• Include interpolation and extrapolation questions whenever possible. Students need to be able to predict new outcomes based on the data shown on a graph.

I hope these reasons will convince you to include more tabling, graphing and analyzing of information.  But, please!!!  No graphing calculators until your students are proficient at graphing and data analysis skills!!!  I firmly believe the calculator is crippling our students.  The calculator is a wonderful tool.....but AFTER the student can do the skill without the calculator.

If you need help with incorporating more graphing and data analysis into your classes, these resources will help:

Tabling, Graphing and Analyzing Data - PowerPoint with Notes for Teacher and Student

Graphing Practice Problems - Great graphing practice with critical thinking questions.

Graphing and Data Analysis - This is a free download that provides good review and reinforcement in graphing and data analysis.

Graphing, Scientific Method, and Scientific Writing - More great science skills practice!


The following lab activities require graphing as a means of data analysis:

Using a Graph to Find Area - This is another free download and a good graph is the only way to solve the problem.

Lab:  Acids, Bases and Cells   Requires extensive graphing of results.

Modeling Population Growth

The Effect of Concentration on the Rate of Diffusion - Another free download!

Teach the Skills, Please!

Science classes can be crammed so full of facts and memorization that I am afraid that we lose site of what science is really all about.  Science is about discovery and inquiry.  Science is about investigation.  Science is about applying a method to solve problems and answer questions.  When I first began to teach, I thought long and hard about what type of science teacher I wanted to become.  In my years of schooling I had science teachers that never did an experiment and made me memorize a bazillion facts that I forgot as soon as I took a test.  I also had science teachers that set me on fire with curiosity and a desire to learn "more."  I wanted to become a teacher like this!

It is important to make your science class lab-based and inquiry driven.  As a teacher of biology, I know that Biology is full of facts and details.  I still try to teach all of these facts, but the facts are mixed in with as many science skills as possible.  No matter what the topic, you can have the students graph, analyze, predict, and describe.  Students need to be taught to design and carry out a controlled experiment.  At every opportunity, I ask my students, "What do you THINK would be the affect of changing this variable?"  And as often as possible we go to the lab to see if their predictions can be proven or disproven.


When I first began to teach, the science portions of many standardized tests were testing the students to see if they knew the "facts."  This is no longer the case! When I took the ACT, I received a score in "Science."  When my daughter took the ACT, she received a score in "Science Reasoning."  Standardized testing in science has changed!  The students must be able to read and comprehend scientific passages.  They must be able to analyze graphs and charts.  If you are not teaching these skills to your students, then you are not preparing them for these tests.

Please don't think I am a proponent of "teaching to the test."  Nothing could be farther from the truth. If you are teaching the necessary problem solving and critical thinking skills, your students will ace these tests.

What have I learned after 31 years of teaching science?

• If I teach the necessary "skills" first, the "facts" will fall nicely into place.
• Spending extra time at the beginning of the school year on graphing, metric system, experimental design, scientific method, and math skills such as scientific notation and dimensional analysis will make the rest of my school year much, much easier.
• The skills we teach in science class are life-long skills.  By teaching critical thinking and problem solving, we are preparing students to be competent in whatever they decide to do as adults.

If you are a biology or a life science teacher who is wondering how to get started, you might want to give some of these activities a try.

How to Write a Clear and Concise Lab Procedure
Graphing and Data Analysis
Using a Graph to Find Area
The Student-Designed Experiment

Laboratory Safety

 

The takeaway from this blog post is simple:  You must teach a deep and thorough course on laboratory safety to the science students in your class EVERY. SINGLE. YEAR!  It's not debatable or open for discussion.

{{ Insert whining voice here. }}  "But my students have heard this so many times before.  Do I really need to make them sit through it again?"

YES!  It doesn't matter how many times your students have received lab safety instruction in the past.  It is your duty, obligation, and responsibility to ensure the safety of your students while they are in your care.  Can you imagine the nightmare if a student was injured in your lab, and you had to admit that you had not taught a lab safety unit?  All teachers who teach science......please listen to me!  You must cover lab safety thoroughly and appropriately for the students you teach.  If an accident should happen while the child is under your "care", you must be able to prove that you provided instruction in lab safety.  If you are not teaching the lab safety rules, then you could be found negligent in the event there is an accident in your class.

Lab safety instruction should be the first unit you teach at the beginning of each school year.  Since I am a high school teacher, the lab is an important and integral part of my class.  In all my years of teaching, I have been fortunate that there has never been a serious accident in my lab.  I have had a minor cut or two, but nothing more serious than that.  I attribute my great safety record to the fact that I stress lab safety on the first day and continue to stress it all year long.

What are the elements of good lab safety instruction?

• First and foremost, students must be given a paper copy of all lab safety instructions.  I use a PowerPoint presentation that is packed with pictures and photos.  Fun images and lots of color will help keep your students interested and engaged as you go over the rules.  I give my students an outline of notes that they complete as we go through my PowerPoint presentation on lab safety.
• Lab Safety Contract:  Parents must receive a copy of the lab safety rules.  Have the parents and the students sign a Lab Safety Contract and keep these on file on year long.
• Student Medical Form:  I require that each student complete a Medical Emergency Form.  This form is sent home to parents to give the parents the opportunity to list any "conditions" that I might need to be aware of.  I once had a student who had very severe mold allergies.  She was excused from doing my mold lab.  I have taught several students with peanut allergies who were excused from my "Energy in Peanuts" lab.
• Students are not allowed to go to the lab until they have returned a signed Lab Safety Contract and a completed Medical Emergency Form.
• Take your students to the lab and teach them about the lab safety equipment.  I have a first day activity that students complete when we visit the lab for the first time.  Students are instructed on how to use the eyewash fountain and safety shower.  Students are shown the location of the fire extinguisher, fire blanket, and fire alarm.  Students are informed on how to exit the lab in case of an emergency.
• Lab Safety Quiz or Test:  Students must be tested on the safety rules.  My students are required to score 90% or better on their lab safety quiz.  If they score below 90%, I require them to take the quiz again until a 90% score is obtained.

I love the old saying, "An ounce of prevention is worth a pound of cure."  This is so true in relation to lab safety.  Make safety instruction a priority and keep your students safe!



If you are looking for resources to use in your classroom, click on the images below to check out these in my TpT store:

                     

Have you read this book?

This is a "must-read"!

I just finished reading one of the best books I have read in a long, long time.  It is called "October Sky".  It is an older book (1998), but I just came across it this summer when someone mentioned to me that it had been made into a movie.  This book would be appealing to any teachers, but science teachers will especially love it.

I am not going to give anything away, but this book is about the "rocket boys".  It is placed in the 1950's and early 1960's, and is a true story about a group of boys living in a coal mining town in West Virginia.  They teach themselves to build rockets, but more importantly they (and some key teachers in their lives) teach themselves that they can overcome hardships and can accomplish anything if they work at it hard enough.  It is an amazing story of what can be earned by hard work and dedication.  I cannot wait to see the movie.  I have just added it to my NetFlix cue.

I highly recommend this book.  It is well written and you need not be a science geek to enjoy it!