• Keep the same partners from the last class.
• Feel free to take a piece of fruit.
• No handouts!

Overview

• Preliminaries.
  • Admin.
  • Upcoming Work.
  • Extra Credit.
  • Questions in preparation for quiz.
  • Questions on Scheme.
  • Quiz!
• Lab.

Preliminaries

Admin

• Lots of preliminaries today!
• We (almost) always have a pot of hot water going in the CS commons for students taking CS classes.
• When would you like mentor sessions?
• The index cards in the back of the room are to support your note-taking systems.
  • I would recommend using the white cards for vocabulary.
  • I would recommend using one color for grammar (syntactic structures).
  • I would recomment using one color for algorithmic concepts.
  • You can think about how to use other colors.
  • Please be responsible in your consumption of the cards.
• In case you didn't know, you can submit questions anonymously via the "Submit Questions" link.
• No attendance today; the quizzes serve for attendance.
• I keep eboards for the review sessions, too. You can find links to them in the obvious places.
• I told you on Wednesday that I keep changing the number of key things that can go into algorithms. I realize that I left out one in our discussions: You need to rely on basic operations that the person or device carrying out the algorithm already knows.
• The CS tutors start on duty Sunday night 7-10 pm.
• Since it's weekend, a few reminders.
  • Consider in advance what you want and what you feel comfortable with.
  • If you choose to partake, please partake responsibly.
  • Remember that consent is difficult to give or receive if you have been partaking.

Upcoming Work

• Lab writeup: Problem 2. Due Monday at 10:30 p.m., but preferably before class. http://bit.ly/151-2015S-lab03.
• Assignment 2 distributed.
  
  • Due Tuesday at 10:30 p.m.
  • I have assigned partners for the assignment.
  • I will give you five minutes at the end of class to find those partners.
• Readings for Monday:
  • Symbolic Values
  • Numeric Values

Extra Credit Opportunities

Academic

• Friday, 12:10 p.m. (TODAY), JRC 224A (Day PDR), CS Table, "Computer Programming as an Art" (copies outside my office)

Peer Support (Morning Section)

• Swimming, Friday, January 30, 6:30 p.m., Osgood Natatorium
• Swimming, Saturday, January 31, noon, Osgood Natatorium
• Julia's radio show, "The Hot Box". Wednesday night/Thursday morning 1:00-2:00 a.m.

Recommended Events (no EC unless mentioned above)

• Belly Dance Club, to be scheduled
• Salsa Club, Tuesdays at 7pm and Sundays at 2pm
• Meditation group, Wednesdays at 9:00 and Sundays at 4:00 in CRSSJ
• #OneGrinnell, Wednesday, February 4 at 4:15 p.m.

Questions on Algorithms

Questions on Scheme

What is (square 4)?

Possible interpretations: Compute the square of 4, compute the square root of 4, draw a square with side-length 4. square means "multiply by itself". Square root is written sqrt. "Draw a square" does not have a single command.

Quiz

• The ideal is ten minutes.
• But if you need a few minutes longer, that's okay.
• Whichever partner finishes first should start getting the lab set.

Lab