Geometry – Logic Stuff

I’m totally reducing the amount of time I spend on this next year. But I’m blogging out what I did just in case you teach it as well.

Things I liked (in order that I taught it):

Inductive and Deductive reasoning sort – I made a card sort with inductive and deductive reasoning examples.  I had the kids sort the cards with zero information, then tell me what they felt was different about the two sets of cards.  They did a great job!  I’m not including my cards because I need to change them next year.  I will only do words on both types of cards, and no patterns or numbers.  A few students took inductive to mean “numbers” or patterns only, and deductive to mean “words”.

I need to spend more time turning statements into conditional statements.

Conditional / Converse / Inverse / Contrapositive Activity from Sam and the great folks at PCMI.  Wow – what a great activity!!  TIPS:

  • It takes a few days but it is worth it!  All students were very engaged the entire time.
  • DON’T LET THE STUDENTS WRITE THEIR OWN STATEMENTS.  Use the ones Sam etc. wrote.  You will thank me later.
  • It is “paper intensive” so make group packets before they come in to preserve your sanity.
  • I put the directions in a picture frame so students could see it more easily as it is a “directions intensive” activity.  They did well and I love when they practice following directions.
  • After the posters were all finished, I had students do a “gallery walk” with post-its so they could make comments on other posters in case a student got the truth value incorrect.  This was great!

Symbolic Logic Proofs – I made cards for them to refer to.  They used them often.  We made “index card pockets” in their graph books to hold them.  I loved these things!

Proof strips – I laminated card stock and we wrote on these to re-arrange the statements.

Post-it flags – I also let them use post-it flags to write the givens on so they could be easily rearranged.

I also combined this with Speed Dating for the win.  I don’t think I can ever thank Kate enough for Speed Dating.

I did another sorting activity thanks to Pam Wilson’s intro to logic post.  This went well!   I let them sort on the floor if they wanted and then check their answers with another group.