Maybe I shouldn't have started this blog now, not with everything that's been going on.

In my Mathematical Methods 1 class last Friday we had our sixth quiz (fifth one that is fifty points). As usual, I was the one who typed down the questions, but I waited for David to arrive before I had it photocopied.

Just like I informed my class the day before, I had a question asking for the median of a triangle given the coordinates of the vertices.

After that were questions on getting the equation of a line given one point which is on the line and the equation of another line which is either parallel or perpendicular.

Combining two of the topics covered there were also questions that gave two lines, and asked for the student to determine if they were parallel, perpendicular or neither. If they were not parallel, the student had to solve for their intersection by elimination method.

There were two pairs of equations for lines given whose solution set had to be attained by graphical method, two by substitution and two by Cramer’s Rule (which, I had mistakenly searched for the other day as Kramer’s Rule).

David asked the first part to be cut out though because it turned out that he did not tell his students that those were to be part of the quiz. He also just bunched the other sets of lines together with general instructions that they could solve those five using any two of the four methods given, as long as all methods are used at least once.

I also assured him that all the equations had solution sets or intersection coordinates that were integers.

But it wasn’t until the class started that I realized the two sets of equations I had initially placed under graphical method had fractional coordinates.

Blame it on an error I had copying formulas when I tried to graph them out earlier using a spreadsheet software. I should have suspected something when the numbered pairs both had the same values.

Anyway, besides solving them right then and there without any paper, I also had to find out what was the least change I could do to the equations so that they would now have whole number intersections.

For one of the pairs, I just had to change the sign. For the other, I took out the coefficient (effectively making it 1). This was the only equation in the quiz where the coefficient of one of the variables was zero and thus resulted in either a horizontal line or a vertical line. Unfortunately, my students seem to have forgotten to review that part, so I had to write summary notes for them on this subject on the board.

I also had to draw the triangle for the first part on the board, with the midpoints all labeled for uniformity. Lastly I had to provide sample final answers for determining the parallel and perpendicular lines.

It’s a wonder David wasn’t didn’t reprimand me for going to his room several minutes apart to tell him about the two corrections after the students had started answering the quiz.

And that’s last week. This week’s classes starting from Monday will be discussed tomorrow. Those who are finished copying what’s on the board may leave.