Measurement Task

This week's task coincidentally actually tied in with my lesson. The task called for the children to trace the outside of their hand and measure it using unifix cubes. The teacher left it open ended--she did not tell the children how to measure. The "big idea" of this is to define what it means to measure something, and are there different ways to measure the same thing? This task gets to the root of measurement and can serve as a base assessment and introduction to words like width, length, how tall, how wide, and possibly even area.


I predicted 3 ways the children could approach this problem. The first way would be for the children to use cubes to comepletely fill the white space of their hand--basically to find the "area" of their hand. With this method the child would be measuring how much space their hand takes up (in relation to unifix cubes). The second way the children could measure is to put the cubes one after another along the width of either the wrist, the palm, or the finger. This would show children that not all parts of the hand are the same measurement, and would start to use mathematical vocabulary like width, how wide, same/different, and comparisons. The third way would be to put cubes starting at the wrist/bottom of the picture and continuing up to the tip of a finger. This would show how long the fingers are and introduce vocabulary like how long, length, same/different and comparisons. The student's whose work is pictured above chose to use the first method-he used cubes to measure the entire space his hand took up. He said
my hand is 14 cubes" though he did not specify a unit (length, width, etc). This shows me that he understands the basic concept of measurement as the amount of space an object takes up and assigning a numerical value to that, but not the vocabulary of length, width, height, etc or the way to distinguish between the different values of measurement.

Some questions I have to follow up or extend this task:

1. The students were often frustrated because the cubes were often thicker than their fingers so they crossed the lines they traced. How could this activity be modified (either the task itself or the materials given) to approach the same concept and limit the frustration of the children involved?
2. How could a discussion be used to extend the concept taught in this task? The students pretty much traced their hand, measured it, and then turned in their work. Would a large group discussion and comparison be beneficial with this type of task?
3. What other objects could the children measure?