Encouraging Academic Honesty

Dan Ariely concludes (video by RSA) that making people think about morality increases the likelihood that they’ll act honestly.

People try to balance the benefiting they gain from cheating against being able to feel good about themselves by being honest. While very few people tend to cheat a lot, many people cheat a little and self-rationalize their dishonesty.

Our school has adopted a short honor code that we’ll ask students to write at the top of tests and other assignments that is intended to remind them of their moral obligations.

Based on one of Ariely’s other conclusions, I’m also considering having students confess their in-class transgressions — talking out of turn; improper use of technology — every month or so, since this type of thing also seems to encourage probity.

The Dish

Finding Where Two Lines Intersect: Khan Academy Lessons

Khan Academy videos on how to solve systems of linear equations:

Use a graphing calculator to double check your lines, or use WolframAlpha, or use my simple line grapher.

by Graphing

Video: Solving Linear Systems by Graphing

Most algebra texts have good problem sets for practice (Khan Academy does not – as yet).

by Substitution

Moving from the more intuitive, visual, graphical method of solution to the more exact algebraic methods, we start with solving by substitution.

Video: Solving Linear Systems by Substitution

Practice Set: Practicing Systems of equations with substitution

by Elimination

Video: Solving Systems of Equations by Elimination

Additional Video: Solving systems by elimination 2 (on YouTube).

Additional Video: Solving systems by elimination 3 (on YouTube).

Practice Set: Practicing Systems of equations with simple elimination

The Mathematical Logic Behind Billions, Trillions and Standard Form

A billion, in continental Europe is, a million squared ( 1,000,0002 = 1,000,000,000,000), but in the English speaking world, a billion is only a thousand million (1,000,000,000). numberphile goes into the beautiful, mathematical logic of the longer form (i.e. the continental system).

Of course, the “simplest” system, which avoids all the potential for miscommunication, is the standard scientific notation, where 1,000,000,000 is written as 1×109 (or just 109).

The Dish

Resonance Frequencies: MythBusters investigate Tesla’s Earthquake Machine

The whole episode is worth watching, but this little section (at 10:52) of MythBusters’ attempt to build an earthquake machine there demonstrate the resonance frequency in a water tank provides a nice visualization.