Measurement Case Study

In Barbara’s case study her students know that when you are measuring the length of something that you must start at one edge and measure straight across to the other edge. I think that they understand that your units need to touch and that you should not leave space in between. However, they seem to think that you can use different types of units as long as you get from one edge to another. For example, they are trying to use books and baskets at one time.

Often time’s students get confused and think that bigger numbers in measurement mean bigger units. In the Rosemarie and Dolores case studies they are working through this misconception to help student’s understand why that is not correct.

In the Dolores’ case, the students were comparing a measurement at home with their parents. Students were identifying the correlation between parents and students that had about the same size feet and this caused their measurements to be close. They also noticed that one of the biggest measurements that differed came from one of the smallest students in the class. They understood why that was possible because they knew he had a small foot and that would be a big difference from his father’s foot.  

At the end of the study Les finally gathers his thoughts on this topic and proudly states “big hands and feet get low numbers and little hands and feet get high number because little things take up less room.” This is a great definition that proves to his teacher that he has established a firm understanding between a unit size and the measurement that it results in.

In the Rosemarie study, Miriam also displays knowledge of the correlation between unit size and the overall measurement. She states “I think Gita has the biggest foot because it took fewer of her foot lengths to measure the doorway. The smaller your foot is the more feet you need to measure something.” While her classmate Courtney display the misconception of the bigger the unit the bigger the measurement number. She states “I just looked at the numbers, and Miriam has the highest number of foot-lengths, so I think that her foot is the biggest.”

In Mabel’s case study the students are focusing on ways to use a ruler to measure something that is longer than a ruler. They are working hard to make sure that they do not add any extra space when moving the ruler from one spot to the next. They determine that it is easier to use two rulers because then you do not waste space in between. In Jose’s case study they have moved on and are working to make sure that they start measuring at the correct spot on the standard measuring tool. They see that you must start at the correct spot and end at the correct spot, while taking in to consideration any extra space on the measuring tool. If you do not do it correctly each time your measurements will not be the same.

Barbara’s students are going to have to understand the correlation between the size of the unit and how that effects the overall measurement. They will then work to make sure that when they are using a tool if they do not have enough to go across the entire length, they will have to figure a way to get the entire measurement without leaving spaces. They will also have to learn how to properly use standard measurements. It was interesting to see this alignment across grade levels.