I teach fifth grade.  My students are 9 and 10 years old.  They are nice kids, and usually well behaved (well, ignore that earlier post about the fight). 

This is a diret quote from my new math curriculum.  See if you can spot the potential problem. 

"Demonstrate how you want students to shake and toss a set of 10 thumbtacks.  Then distribute 1 cup, 10 tacks, and a stick-on note to each partnership.   Each partnership then makes a totaly of 10 tosses of 10 thumbtacks and records teh results of each toss in their journals."

Have you spotted the potential problem?  Has whoever wrote this ever seen a ten year old?  Thumbtacks?  Are you kidding me?  They want me to hand out a cup of 10 thumbtacks to 15 groups of 2 in my class.  That is 150 thumbtacks.  And then say to them "toss these 10 times"?  Really? 

I asked my students what would happen if I handed them cups of 10 thumbtacks.  One student raised his hand and said "a lot of owies".  

The goal of the activity is to predict and then verify the probability that the tack will land on the flat side up or point side up.  I am baffled as to why this particular activity was chosen to reinforce this idea.  Has the author of this curriculum never seen or read about a kid putting an tack, point side up, on a chair?  Seems like that is a classic.   

At first we thought it might be that it was not a 50/50 chance, and that there was some magic about thumbtacks.  Turns out, there is a 50% chance the tacks will land point side up.   Why could we not use pennies?  Or even shank buttons, which resemble thumbtacks?  

We did do the task, but with me going from group to group, modeling the tossing of the tacks and then monitoring as the students, one by one, took turns tossing them into a tray and recording how they landed.  I would have much prefered to have them do this on their own, but I was not going to risk the owies.