Over the past 35 years I have taken good activities and made them better multiple times. Sometimes the improvements have been because of past experiences and sometimes the improvements have been because of new tools.
This past week, I took a project that I have done with various grade levels and in various degrees of depth. It is a project that includes paper folding and exploring exponential growth and exponential decay. Most of the time it includes a Myth Busters video clip about folding paper a maximum number of times (link below).
This activity explores the exponential growth of the thickness of the paper as they fold it and the exponential decay of the area of the top sheet as they fold it.
This past week I created a Desmos Activity to complete the whole project and most of my Algebra 1 students completed it in a one hour period and felt lots of success. I didn’t show the video, but I handed them a sheet of paper to do the folding. Good old fashion manipulative married to technology. The Desmos Activity link is included below.
In the past some students got lost in the hand calculations and tedious graphing, and missed the AAHHH moment (on day 2 with the babysitter project they did graph on graph paper, which they needed to develop).
I followed up the next day with a babysitter project modified from a Maryland CCRG Algebra Task Project lesson (link below). I also included a document link with my modifications to make it a one day activity (link below).
This was an introduction to exponential functions with no pre-teaching. After two days I felt very confident that my students understood the difference between linear and exponential functions and could identify key features of each in a story, table and a graph. They also clarified slope and y-intercept for lines, and discovered exponential growth factor and exponential decay factor for exponential functions. They could also write an equation for exponential growth and decay. We will need some reinforcement on these next week.
Myth Busters link to exponential growth: https://www.youtube.com/watch?v=kRAEBbotuIE
My Desmos Activity Builder on exponential growth and decay: https://teacher.desmos.com/activitybuilder/custom/566983bb412bcf1d06986c70
Maryland CCRG Algebra Task Project link: https://commoncorealgebra1.wikispaces.hcpss.org/file/view/A.CED.1+Babysit+Task.doc
My one day babysitting project: https://www.dropbox.com/s/bbj4spkmtar950k/Babysitting%20task%20sheet%202015.docx?dl=0
Here is a link to other Desmos Activity Builder activities I have used in my classroom this year: https://docs.google.com/spreadsheets/d/1ZlAPdLDSTeTF54gHiGrSQx0d4J399Tnl1fPweMpChc8/edit?usp=sharing