Chemistry students and math: question

Discussion in 'High School' started by leeshis0019, Jul 21, 2014.

  1. leeshis0019

    leeshis0019 Companion

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    Jul 21, 2014

    Okay, so an issue that seems to be cropping up everywhere [around here at least (GA)] is that in the sciences we get students that don't understand how to solve for variables. As an example, D=m/V...given mass and density solve for volume. There are plenty of students that can't do it even when you show them. Now I have a lab that I want to do that works out how density works and how mass and volume play a role and I think it will help some students, but I can see it not reaching everyone simply because when they see mathematics they shut down.

    That's an extreme example because in a subject like Chemistry or Physics you can have many more variables and we are encouraged to give students word-problems rather than straight-forward plug-and-solve problems. I don't mind this and I think the students get much more out of word-problems, but does anyone have any tips on working with those students that have issues?

    When I did gas laws in Chemistry there were so many formulas that I created a worksheet that had them filling in variables, telling me which formula they would use and essentially going through the steps over and over and over. There were students that told me they were done showing the steps after one or two problems (those more gifted students), students that just did what they saw (non-assertive or they just don't understand) and then students that simply could not do it at all. I worked with them individually and paired them with other students, but something was not clicking.

    It was the most stressful experience as I was student teaching because I felt like I was failing those students despite trying hard to help them the best I could. There was a time-crunch because of massive amounts of testing a few weeks after this unit so it was somewhat sped up and we ended up doing a lab where they collected oxygen and connected that to our earlier lessons on...well...everything about chemistry (moles, conversions, chemical reactions, etc.) and I was still just upset about the students that were behind not because they couldn't understand the chemistry, but because they struggled with the mathematics.


    So...are there any chemistry teachers or physics teachers that struggle with this or perhaps you used to struggle and found some means of relieving that struggle. I thought perhaps changing the assessment to be more concept based rather than formula based would help, but there were restrictions on what I could actually do and that never came to fruition.


    Or any teachers I suppose. These are students that I felt like should be in a less rigorous or abstract science, but at the same time I don't think they should miss out on the experiences they can have in a chemistry or physics classroom. These are two huge science courses that branch out into a mass collective of careers.
     
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  3. lucybelle

    lucybelle Connoisseur

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    Jul 21, 2014

    They have to know how to solve for variables. When the kids don't understand I start with very simple examples: 2x=4 what is x? They all know, but then you make them actually work out the problem. Then 2-x=0, x/2=2, 2+x=4.

    Also, for every problem I *always* make the kids write an "info box". They go through the problem and underline all the givens. On the side they write each given, for example: m= 5g, V= 10mL. Then they write down the equation they think they should use, they should come up with D=m/V. Then they write what they need to find- D=? They draw a big box around that information. When they solve they re-write the equation, substitute in the givens, and then solve.

    ALL kids MUST show this work every time. I don't care how smart they are, they write an info box and show all their work. I've had lots of kids complain about the info box at first, and then when we got to harder problems tell me "the info box is so helpful, thanks for making us do it".

    Thought of something else- do you let the kids use calculators? I always let them use calculators. I tell them it's not math class, to let the calculators do the work. But I need to see their thought processes.
     
  4. 2ndTimeAround

    2ndTimeAround Phenom

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    Jul 22, 2014

    Yes, I have many students that cannot solve for variables.

    This is not part of my curriculum. I get quite upset when students come in not knowing how to do it. I spent a lot of time in class one semester, time that I did not have, rearranging formulas and reteaching this concept. I finally gave up. The next semester I gave a "pre" worksheet during the first week of class. Students that could not solve simple word problems and rearrange formulas were told they had four choices: drop the course and take an easier science requirement; learn how to solve the problems on their own time; attend scheduled tutoring sessions after school where I'd teach the concepts myself or prepare themselves (and their parents) for a D or an F in the class. I sent home the graded worksheet and a note stating the above and required a parent signature.

    It helped in a small way. I still had plenty of students that refused to give up their time to get the foundation they needed. After a few low scores, and a reminder of the note I sent home, most of the students got extra help on their own.
     
  5. leeshis0019

    leeshis0019 Companion

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    Jul 22, 2014

    I don't think I'll have that kind of leeway unless it was an advanced class (where I can recommend they move down).

    My idea was just giving them a math quiz where they solve for variables and solve word-problems similar to what they will see in the class and give them feedback using that. Sort of a preemptive strike, so-to-speak, to let them know what kind of grades they can expect if they don't work on those math weaknesses.



    Edit: The students could use calculators if they want to.
     
  6. Mrs. A

    Mrs. A New Member

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    Aug 26, 2015

    I also teach Chemistry in Georgia, student math skills are very poor. Many can't even use the density triangle correctly. For thermo q = mc(delta T) It was impossible for me to get to the point to solve for anything but q. (it is ALWAYS q divided by the other two) Many could never do this! I thought I must be an awful teacher at first. I happened to have a 6th grader at home so I did an experiment. I taught her the lesson, gave her the same assessments and she very easily understood the concepts and performed much better than my 10th graders. (She is not a math/science kid, but she was at one of the better elementary and middle schools.)

    The county I used to teach in had "suggested pre-requisites" but students and parents insist that their child is more advanced and they ignore them. My school would not support putting students in appropriate classes that meet their abilities so a parent call is all it takes.

    Students entering chemistry must have completed Geometry and be enrolled in Algebra II. Students taking geometry and chemistry at the same time always struggle with the math. While they don't need geometry to be successful they do need the additional algebra skills and abstract thinking skills they will get while in Algebra II and the needed maturity that develops over time.

    When I have honors students who are not in the appropriate math I let them drown. It is not fair to water down and slow down the curriculum just so they can pass.

    I worked very hard to place students in the correct class and level of class by giving them a math assessment before they are placed in Sophomore classes during their Freshmen year. A minimum score is needed to be placed in honors and many are told they will not do well in chemistry and need to wait until Junior year to take the class to get more math. Again, parents override the teacher recommendations. My data over three years correlates success in chemistry with my recommendations.

    The good schools near me hold fast to the pre-recs and teach at a much higher level. These schools are in high SES areas. One of the biggest issues is where to put them their Sophomore year. Most take Bio first year, and since they can get HS credit for the Physical Science they take in 8th grade there is not a great alternative class. Our school did away with offering Physical Science and place students in Earth Systems sophomore year. (Not a great alternative just a holding place for a science student to mature.)

    I now am teaching at a start up private school and have students with a little better skills but not where they need to be. I still teach as much math as chemistry.

    Bottom line: our system is failing students and passing them on (especially in math) when they have not adequately demonstrated their skills.
     
  7. beccmo

    beccmo Comrade

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    Sep 19, 2015

    I see this in my Physics classes. I spent the first 2 weeks just working on Unit Consistency-evaluating the units in problems to determine final unit of answers-and conversions. We are now at the part of the Motion unit where there are so many formulas that some students are freaking out.

    I had them create a table of variables we use and the most common units they will see for them. This helps some with interpreting story problems and they are able to assign the correct variable to given information more frequently.

    I provide all answers to practice and homework problems, so it is up to the students to show me how to come up with those answers from the information given.

    There is NEVER a time I will allow students to not show all the steps to solve a problem. I equate problem solving to essay writing. An essay has an introduction, supporting detail, and a conclusion. Problem solving should do this same thing. Showing all the work to solving a problem is the supporting detail. Students should know the final units their answers should have. Making sure units cancel properly in your final equation is important--so include them in your writing!!

    I have many students who can plan a solution properly, but make dumb mistakes with their calculator because they cannot understand how to use it properly. If all work is not shown it isn't possible for the student or myself see if an error made was in the approach to solve or with calculator skills. After a while students become better at recognizing and correcting their own mistakes.
     
  8. PoliticalFutbol

    PoliticalFutbol Rookie

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    Oct 25, 2015

    Show the students all of the possible formulas. For example, D = M/V, M = DV, V = M/D. Do experiments that directly verify each. Then ask them "Do you want to memorize all the formulas or just one?" Similarly show the many other formulas that we memorize and their variations.
    d = vi t + 1/2 at^2, a = i t^0.5, 1/f = 1/di + 1/do, p = mv, V=IR, etc., etc. Again, ask, do you want to memorize all of the formulas?
    Explain there are millions of formulas, most of which we will never use. We must know math so we will be ready to access the ones we need when we need them.
     
  9. jw12

    jw12 Rookie

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    Jul 15, 2016

    This is a HUGE problem in my school (I'm in Ohio btw). It amazes me how students can go through 3 years of high school, end up in a senior-level physics class, and are unable to solve even the simplest equations!! My fellow chem and physics teachers want to pull their hair out. We haven't found any solutions, but I think that its the students' mindset that plays a role...

    I was in this very situation going over a simple 3-term equation (solving for time in v=d/t), and the kiddos couldn't do it. When I said (out of frustration!) that it was basic algebra, one young lady spoke up and said, "But this isn't math class." They really don't see the connection between math and science... they don't understand how the subjects are related. And I don't know how to make it clear to them.
     

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