Experiences

Linear equations and inequalities

Zuzana Zuštinová

Slovakia

High Secondary School

Maths

Teaching in class

Direct

In the class I have already gone through:
- Linear functions
- Linear equations and inequalities, systems of inequalities

During the previous class I had a presentation in which I reflected on the system of equations and explained graphically a set of system solutions. I wrote on the blackboard a simple system of two equations. From each one I derived the y, identified the functions and created two empty tables. Then I showed the students how to fill in the tables with numbers and how to construct two graphs in one coordinate system. I reminded the students that I will want to see all their workbooks during the class. The first student had more points in the chart as needed and he did not connect them. The second one created two separate graphs. Other students did nothing.
I asked a student to come in front of the class and do the task with my help on the board. We stopped at filling in the tables. He certainly did not understand that f: y = 2x + 4 reads f divided by y... He did not know where the point [0; 4] is but we somehow managed to make the graphs. I wanted him to mark down the intersection point of the functions as a P. He marked it with a small letter p!
During the time he worked by the blackboard other students showed me their workbooks. Several had the chart correctly. Some had errors, which I pointed out to them so they could fix them. All of them received a grade.
I dealt with the identified weaknesses of the basic knowledge from elementary school by projecting images from my presentation on analytic geometry. In Annex I send it to you.
After this, I checked that all students had the chart in their workbooks. Three of them did not have it, therefore they got the failing grade, which I think I definitely regret more than they do. One asked how to mark the intersection, even though it was clear on the board. During the next class we will solve the equation systems by adding or subtracting method. Although I learned of a great lack of knowledge of my students, I consider it to be a good class. In the future I will check whether the students made up their basic knowledge of geometry.