Month: October 2016 (Page 1 of 2)

OpenLab #6: Proof Journal

Your assignment for the next week is to try to prove the conjecture that your group created in class on Tuesday, 10/14/15.  You must spend at least 90 minutes working on this.  Trying to prove something can consist of many different activities, such as the following (you do NOT have to do all of these things – you can choose how to spend your time – they are provided for inspiration only).

  • coming up with ideas, and testing them out (for example, by creating puzzles and trying to solve them)
  • trying to understand what the conjecture says
  • trying to solve puzzles that other people created
  • trying to create puzzles (and solve them yourself)
  • communicating with other members of your group (talking, emailing, etc.)
  • trying to write down a proof
  • other stuff…

As you work, keep track of what you are doing, thinking, and feeling (this is metacognition – an idea that discussed way back in OpenLab #2).  What did you do during the time you spent?  Did you create any puzzles?  Did you solve puzzles?  Did you change your mind about whether the conjecture is true or false?   Did you have any new ideas about how to prove the conjecture?  Did you have any ideas that you gave up on?  How did you feel as you worked – were you frustrated/confused/happy/depressed? Why? Did your mood change along the way?

Assignment (Due Thursday, 11/3/15):  Submit a journal of your efforts in the comments below.  Your response should be at least 300 words.  Describe what you did during the 90 minutes you worked, and express in some way what you were thinking and feeling during the process.  Your response can include puzzles (use or other work you did along the way.

Extra Credit.  Respond to a fellow student’s comment.  Did you do similar things? Different things? Do you have any suggestions for them? Be kind.




conjecture3 conjecture1 conjecture4 conjecture2

Week 10 Assignments

Written work, Due Tuesday, November 1st, in class:

Chapter 8 p145: 3, 7, 18, 19
Chapter 6 p.116: 3,4,5,8,9
Chapter 7 p129: 5, 9, 10, 12

WeBWorK – none
OpenLab – OpenLab #6: Proof Journal due next Thursday, November 3rd, in class.

Office hours cancelled today (Tuesday, 10/25)

Hi everyone,

I’ve been asked to cover a class for a colleague in the math department today (Tuesday, 10/25), and it overlaps with my office hours.  However, I should be able to arrive at our class a few minutes early, and I’ll be able to spend a some time at the start of class answering questions.

Prof. Reitz

A note about grading written proofs

Hi everyone,

I’ve been enjoying reading your first proof-based homework, and I wanted to give a quick description of how I grade them:

Odd problems are worth 4 points, and are graded (almost exclusively) on completion – did you do the problem? If so, you get 4 points.  I will *not* deduct points for minor errors.  I *may* deduct points if I notice something really, really wrong.  I encourage you to do these problems, and then take a look at the answers in the back of the book – this is a great opportunity to see how proofs should look, feel, and read.

Even problems are worth 8 points.  I will be grading these much more carefully, and will be picky about things like using words (not just symbols), giving reasons for each step, and not skipping steps.  Your absolute best opportunity to improve your proof-writing may come from looking at what you missed in these problems!  If any of my comments are not clear, feel free to ask me about them.


Prof. Reitz

Week 9 Assignments

Written work, Due Thursday, October 27, in class:
Chapter 6 p.116: 3,4,5,8,9
Chapter 7 p129: 5, 9, 10, 12
      **NOTE: this assignment is due on Thursday, instead of on Tuesday, because we have our second exam on Tuesday.
WeBWorK – none
OpenLab – none


In-Class Group Project Activity 10/14/16 – Make and Test Conjectures

NOTE: As a component of OpenLab #5, each person should bring to class a conjecture or question about the Bridges and Walking Tours game.

Group Activity (30 min).  Get into your groups, arrange your chairs in a circle, and take 30 minutes to:

1. Each person should share their conjecture with the group.  For each conjecture, the group should decide if they think it is true or false (or don’t know).  The group should record their conclusion for each conjecture.

2. Choose one conjecture (or create a new one) to focus on as a group.  Your goal for the next few weeks will be to try to prove or disprove this conjecture.  Come up with several ideas about how you might prove it.

Group work due after 30 minutes:  Each group will hand in a sheet of paper with the names of the group members, the date, and the following:
– Each member’s conjecture, along with a brief description of what the group thinks – is it true or false?
– Be sure to clearly indicate which of the conjectures the group has chosen to work on – or, if you have created a new conjecture to work on as a group, include that as well.
– Two different ideas about how you might try to prove the chosen conjecture.

Reflection:  To be completed individually after group work is complete, and submitted on paper with your names and the date.  Take 5 minutes to write on the following prompt:

Briefly reflect on the process of working in a group by responding to each of these points:
1.  Describe something you learned.
2.  Describe something you contributed to the group.
3.  How did today’s work change your understanding of your assigned game?

City Tech email seems to be down – post your homework questions here!

Hi everyone,

I can’t seem to access my citytech email (or the citytech website), at 9pm on Thursday evening 10/13/16 – so if you’ve sent me questions about the homework, I won’t see them tonight!  But I do have access to the OpenLab – if you see this message and have a question, you can go ahead and post it here as a comment, I’ll reply in the same way.

Prof. Reitz


Week 8 Assignments

NOTE: The homework assignment for Chapters 4 & 5 has been modified from the original calendar – it includes two additional problems (and one of the problems is now optional).

Written work, Due Tuesday, October 18th, in class:
Chapter 4 p.100: 1, 6, 7, 15, 16
Chapter 5 p.110: 1, 4, 9, 20*
Odd problems are worth 4 points, even problems worth 8 points.
* (Chapter 5 Problem 20 is optional – solutions will receive extra credit)   
– none
OpenLab – none

Exam #2 will take place on Tuesday, 10/25 (first half of class).

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