I am getting ready to teach my second graders about input/output tables. Yes, in second grade! This is a new standard for us. A standard I have not taught before. I have been racking my brain all weekend trying to figure out how to teach this concept in a way that relates to the lives of my second graders.
While reading the Teaching Addition and Subtraction Using Contextual Problems section in John A. Van de Walle & LouAnn H. Lovin's book Teaching Student-Centered Mathematics Grades K-3 I had an AHA! moment. I LOVE those! The authors tell us that in the United States we don't tend to go deep enough with math problem solving. That we have a tendency to have students solve a lot of problems in a single class period and the focus of most lessons is to get answers right (pg. 71). They suggest however, that if we want our students to construct a rich understanding of subtraction and addition (or any other operation/concept you might be teaching) we should focus more attention on having students solve one or two problems and then give more time to classroom discussions on the "how" and the "why" rather than simply looking to see if the answer is right. This sounds A LOT, I MEAN EXACTLY, like what the new Common Core State Standards are asking us to do.
After digesting this section of text and thinking about what we are doing in the classroom right now I realized that we had the perfect context for some contextual story problems using addition, patterning and input/output tables.
Currently my second graders are working on a biography research project and are planning to construct a wax museum of historical figures in our gym on Thursday. We have invited our families and they have returned RSVP's with the number of guests who plan to attend. We are also planning to serve our guests cookies and punch to celebrate afterwards.
My plan is to give students the numbers of family guests who plan to attend. I will ask them to work with a partner to figure out how many guests will be attending using the Math Buddy Chat system developed by Laura Candler. After students solve the problem we will look at the different strategies students used and compare our answers.
On Tuesday I will ask students to help me figure out how many cookies we will need to have if we are planning to have enough cookies for each guest to have two cookies each. This is where the idea for the input/output table came into play for me. I will pose the problem to students and have them come up with a plan for solving the problem with their partners. Afterwards we will analyze the problem solving strategies students used. I will guide students towards understanding how they could put this information into a table format to help them see the information more easily. We will then name this strategy (make a table) and the type of table that we created (which of course will be the input/output table).
As I am typing this I am thinking of how we can continue problem solving within this context throughout the week. For example, how many packages of cookies would we need to purchase if 10 cookies came in each package? How much would this cost if each package cost $1.50? Etc.
I am excited to try this with my students and see how this goes as an introduction to input/output tables. I will post the results soon!