## Saturday, February 7, 2015

### Preparing for the new Common Core Test Part II

SBAC High School Calculator
Desmos

Students were required to have two windows open, each taking up half the screen.  This mimics the setup of the performance tasks on the SBAC test (You can log on to the practice test here. Be sure to select 11th grade, and math performance task).  We asked students to download the Chrome extensions Tab Scissors and Tab Glue if their computers didn't automatically create half size windows.

In this task a group of 11th graders was being introduced to regression for the first time.  The problems on the Google doc are modified from the textbook for this class.  The mathematical goal for this day was to find the equation of a linear regression and use the equation to make predictions.  The technology goal was to find needed information and solve problems by navigating between various windows.  Below is one of the problem sets we asked students to work on.

We had students open a separate link to access data so that they could easily copy and paste the data into Desmos in order to find the regression equation.  Below is a snapshot of the data stored in a Google Sheet.

After you copy the data from a spreadsheet, you can go to the first input line in a Desmos sheet and paste the data.  It's as simple as control-C and control-V copy and pasting.  In line 2 you type y1~ax1+b.  Desmos automatically makes the subscripts for you.  Note that we use "~" instead of "=" when finding a regression equation.  See the regression parameters on line 2.

You might be asking why we used Desmos for regression when SBAC has its own regression calculator.  The answer is that Desmos makes regresssion sooooo easy, and it also automatically scales your graph to fit the data (see below).  We didn't want students to be focusing on too many new technology skills for this lesson, so we stuck to Desmos for the regression piece.

Once students found the regression equation, they needed to use the equation to make predictions/answer the questions on the worksheet.  This is the part when we required students to have two windows open side by side (so use tab-scissors and Tab-Glue Chrome extensions or similar.  Some computers/browsers have this feature built in).  The reason we found this step to be so important is that students needed to transfer information between various windows in order to make calculations.  Below are the transfer steps:

1.  Transfer regression equation from Desmos to worksheet.  Desmos only gives regression parameters, so this is not a copy-paste step.
2. Transfer expression from worksheet to calculator.
3. Transfer answer from calculator to worksheet.

We also found that some students weren't able to paste expressions into the SBAC calculator, which further frustrated them if they didn't have two side-by-side windows open.  Below is a screenshot of what students see when they are working with the SBAC calculator to answer questions 9 and 10.

Many students really-really-really wanted to pull out the paper and pencil to do this work.  I don't blame them.  I've never shown my work for a math problem on the computer until I made this activity for students.  Since students will need to show their work on the computer when they take the SBAC test, we need to have some practice doing so in the months leading up to the test.  In scanning student work, the teachers saw that many students did not show their work on the computer, despite explicit modeling at the beginning of the lesson.  For our next activity, we will definitely have some exemplars to share with students as well.  Below is an exemplar for problem 9.

So far we've competed this lesson in 7 classes, and it has gone well with the exception of students not showing their work on the computer.

A few pieces of background info (in case it is helpful):
-This particular school is a BYOD (bring your own device) school, where most of the English and Social Science classes have been using Google Drive for this school year.
-We used Doctopus to distribute the worksheet to students.