Today we introduced the idea of creating an algebraic expression or number sentence using a symbol or letter to replace the unknown number. We introduced this idea by exploring a problem about guinea pigs!
There are 10 guinea pigs in a classroom and two cages. How many different ways can you arrange the guinea pigs to fit into the two cages?
After spending time in groups most students could create the number sentences :
10+0=10
1+9=10
2+8=10
and so on.
Only one group thought to arrange the guinea pigs using turn-around facts by recognizing that putting 1 in the first cage and 9 in the second cage is different that putting 9 in the first cage and 1 in the second cage.
We found that with 10 guinea pigs there were 11 ways to arrange them.
Next we tried the problem with 8 guinea pigs, and then 25! By the end the students discovered that the number of guinea pigs + 1 always equaled the number of ways that you could arrange them.
By the end of the lesson, the students were able to understand that :
NUMBER OF PIGS + 1 = NUMBER OF WAYS and were able to apply this to many different problems. Way to go third graders!
Wow, third graders! Amazing work. So, if there were 50 guinea pigs how many different ways are there to arrange them??
Thanks Elisa Waingort! If there were 50 guinea pigs there is 51 ways to arrange them thank you for commenting on our class blog!
Way to go Kelly! You’ve got it!
Love,
Mrs. C.
This project was so fun. My favorite part was just figuring it out. It was one of the funnest math project this year.( In my opion)
I liked it.
Connor B
http://connorb2013.edublogs.org/
hi guys,
I’m a student this year u guys are lucky to have her all year visit my blog avac2015.edublogs.org