Where Do These Nails Go?
Lesson 7 of 14
Objective: Students will be able to apply measuring and perimeter knowledge to solve a real life problem of building a bat house using only 28 nails.
How to Build a Bat House
To introduce today's lesson, I will begin by showing students images of schematics and photos of bat houses. We will discuss what they notice and how they think a bat house is held together.
I will then model how to view our schematic, with measurements, and I will also assemble a wooden bat house, like blocks, without the nails. The students will be asked later to measure and mark spots for nails, so correct assembly is critical.
During this time, I will also prompt the students to think about how the house will stay together and remain strong. The conversation should turn to using nails.
I explain in Classroom Video: Backwards Planning how I have fundamentally changed how I teach multiplication, and explain the backwards planning that was done to create the steps I just described.
Present the Problem
First we carefully review the assembly of our real world math problem - how do we build the bat house kit. I did rewrite the directions to make the language more accessible, but I didn’t remove the mathematical thinking. Students need to apply their mathematical understandings to reason through the directions. In the Classroom Video: Discourse and Questioning you’ll see and hear us reasoning through these directions as I use discourse and questioning techniques to prompt thinking or ask questions to help students organize and "hear" their own thinking. Note that I do not do the reasoning for my students.
After looking at the proper assembly of the bat house kit, I tell students they will be given exactly 28 nails to put their house together. As a team, they will need to decide how and where to place the nails using equal intervals. This is a rich mathematical task that poses a real world mathematical problem. I know that my students might struggle a bit, but I believe that they can reason through this task.
But I do provide some support. I circulate while they are thinking, and before sending the teams off to solve the problem at hand we discuss possible solutions and strategies, as a whole class.
Measurement and Marking
Student teams are given their box with all of the pieces, the schematic, and the checklist. They go to their designated work space in the room and begin to determine the best intervals for placing the nails. Prior to marking the nail placement holes, the students need to measure and score the wood for the interior slat placement. The objective here is that students will identify where nails need to be placed, and will measure and mark accordingly. Please note, I am not telling the students what those intervals should be. This is a problem that students will solve.
I will circulate and discuss/prompt the student in order to help them arrive at the realization that they need regular spacing. I will also be listening for discussion about key places to mark for the nails. I am looking for strategies here and I need to work quickly to hear the team conversations during their planning time.
Closing and Sharing
As this is a large and ongoing unit with many connected lessons. Due to time, I have chosen to have the students share out what they accomplished and what they may still be struggling with, as an exit ticket.
By doing this, I set the stage for students to respond and help each other at the beginning of our next session. It is also a helpful strategy to help students self assess work and manage and plan what they will do next.
Building a bat house is a rich demanding task, but it is within my students’ reach. It's success depends on many carefully planned elements and a year of working with students to develop their mathematical knowledge, skills, and thinking. I was guided by the Common Core Mathematical Practices, which describe the rigor of instruction. By making my teaching more rigorous I feel I have been much more successful in teaching my students. In this Classroom Video: Exit Tickets, I explain and show you what has changed in my teaching.