Measurement: Comparing Dinosaurs

I will discuss with my students what we have done in the past to measure using objects. I will begin by asking:

Students what do we know about how to measure?

I will guide them towards giving me ideas related to:

• Things must be lined up from tip to tip. 
• We cannot get a correct answer if items are not aligned.

First Graders need to be able to order the length of three objects by comparing the lengths with one another. (1.MD.A.1). They can use the third length to compare the other two lengths and determine which is shorter, longer, or the same. I plan to use several examples o fobjects; pencils (3 different lengths), crayons (3 different lengths) and lengths of yarns (our dinosaurs that we have been studying) and have them assist me in placing them either long to short, or short to long. My gathering spot to examine the pencils and crayons will be around our long table. I will select random students to assist with the examinations and ask the group to agree or disagree by showing thumbs up or thumbs down. I will begin with the pencils and use them to demonstrate how to align them and when we are finished as a group I will ask them to turn to a friend and tell their friend what we did to compare the pencils.  

Now we will compare our crayons. When my students are finished with me around the table, I will send them to their desk and ask them to turn to their neighbor and ask one question about and tell one thing they learned about from this lesson.)

Our finale to this whole group lesson is comparing our dinosaurs. My class has been studying multiple dinosaurs all week; what they ate, where they lived, what happened to them, their size, etc. I picked 3 of the dinosaurs to use for students to compare their size. I used 3 pieces of yarn to cut out the exact lengths of a Triceratops (30 ft.), Plateosaurus (26 ft.), Tyrannosaurus (50 ft.). I will take my class to the hallway and have them sit along the wall and pick volunteers to come and assist me to stretch out the yarn and begin to move them around and discover which dinosaur was largest and which was smallest. Don't forget to label your yarn lengths with the dinosaur names. 

I will use the dinosaur activity to ask some thought provoking questions, but I will ask them to turn to their neighbor and tell their neighbor their answer before I call on someone to share:

• How do you know the Tyrannosaurus was longer than the Plateosaurus? (Because his string is longer than the other one, he was 50 ft. long and the other one was 26 ft. long and 50 is bigger than 26)
• How do you know that the Platesaurus was shorter than the Triceratops? (Because it has the shortest string of all of them; it was 26 ft. long and the others were 30 and 50, 26 is smaller than those numbers.

These are important questions to ask to get them using their critical thinking skills and to encourage them to describe their ideas. Also, it provides them an opportunity to prove to you they understand how to use the measuring tool (yarn) is to be used appropriately. (MP5). This lesson involved comparing lengths which required aligning those objects (tools) in an exact manner to be able to reach a correct answer. These tools help First Graders develop higher-order thinking skills. 

Print and copy the Ordering Lengths Worksheet for each student.

I will have my students practice answering questions about the length of objects and placing them in order by length. The skill of ordering lengths builds their mathematical practice to look for and express regularity in repeated reasoning. (MP8). Students will begin to notice, "if I find the shortest length and the longest length, I can place the objects in order by length." It is a repeated process for them to follow.