Geography: what is a free port?

Tutoring high school, I’ve never been asked this. The tutor looks into a question he’s long wondered about. The phrase “free port” means pretty much what I expected:  a port where goods can be exchanged, duty-free, then reshipped.  As long …

Tagged with:

Perl programming: string conversion to character array

Tutoring programming, conversions between strings and arrays are relevant. The tutor shows an easy way to do it in Perl.   Converting a string to a character array is a common task in small programs, especially ones that accept user …

Tagged with: , ,

Statistics: average waist size of men in America

Tutoring statistics, questions arise from it.  The tutor begins a discussion about some recent findings. Twenty years ago I sold suits.  A good deal of customers had 38″ or 40″ waists.  However, there were more men smaller than that, rather …

Chemistry: parts per million

Tutoring college chemistry, you sometimes get asked about parts per million. The tutor explains a concept more often heard in everyday life than in the academic world. Parts per million, or ppm, is often used to express the concentration of …

Tagged with: , , ,

Math: slope-point form

Tutoring math 10, you cover slope-point form.  It’s usually the most convenient  way to find the equation of a line.  The tutor gives an example. Slope-point form is probably much more popular among university students than at high school. It’s …

Tagged with: ,

Math: Solving systems of equations: Cramer’s Rule

Tutoring high school math, I don’t see this used.  However, I did see it at university.  The tutor introduces Cramer’s Rule. Consider the following problem, common in high school math: Solve the system. 2x-4y=20 3x+5y=-3 If you know determinants (having …

Tagged with: ,

Computer science: the while loop

Tutoring computer science, a tenet you need to impart is the use of loops to accomplish repetitive tasks.  The tutor introduces the while loop. Every programming language I know of has a “while” loop.  A while loop begins by checking …

Tagged with: ,