# Conditional Statements and Law of Syllogism

The other day, I wanted to review conditional statements and the Law of Syllogism before we started proofs.

I split the class into two teams and gave each team a set of cards.  First, I had them practice putting the cards in order.  A few of them had played a version of the game before in middle school, so it went pretty smoothly.  After about 10 minutes, I collected the cards, shuffled them, and passed them back out.  I had the two teams compete against each other.  The winning team got one bonus point.  My kids enjoyed it and I kept hearing funny things like, “Come on guys, look!  If I do my homework, then my parents are happy!”  I liked this because I didn’t have to answer any questions or anything, but my kids were talking about math and working the entire time.  Awesome!

When I brought the class back together, we talked a little bit about starting proofs.  Most kids have heard horror stories about geometry proofs, so I usually like to prep them a little before “the big day”.  I tell my kids that proofs are like a mathematical story.  If you forget a detail of the story, it doesn’t make sense.  Also, if you tell the story out of order, it doesn’t make sense.  Proofs are our geometric story that needs the details in an order that makes sense.

Next, we did an activity that I totally ripped off of Crafty Math.  It was such a good idea and it turned out better than I expected.  Win!  I'm so glad I checked out her blog.  I used the overall idea and copied the robot story.

I put my students in partners and gave each group generic “If…, then…” statements.  They had to cut them out, put them in order, and use the Law of Syllogism to come up with a conclusion.

When they were finished they had to glue them on paper.  I also had them do the same thing with a short story.  If they finished early, they could decorate their pictures.

(Cookie cards are kind of a big deal at my school among the underclassmen.  They buy punch cards for \$10 and can buy treats in the cafeteria with them.  There are these fantastic chocolate chip cookies that are 25¢ each.)  I hung these cute pictures for Back to School Night.  Proofs are next!