After visiting a number of science classrooms last year I began to notice a trend. Many of our students do not have mastery of the most basic of measuring tools - the simple balance scale. As we all know, accurate data collection depends upon the ability of our students to first determine if the balance is accurate, and then for them to be able to accurately weigh an object.
With this in mind I created a simple beginning of the year test which I recommend to everyone. The first part of the test is for each table to determine if the scale is balance, and if not they are to balance it. A mini-lesson may necessary before proceeding. Then, at each table I have place a plastic pencil box with 8-10 objects of different size and weight. Each table has identical objects. For my purposes I include a golf ball, a rubber stopper, a D cell battery, a large metal washer, and a variety of other common objects. In my science groups students will identify each object, weigh it and record the weight. Since each table has the same materials (which I weighed before placing in the boxes to determine each is of equal weight) we can assess quite easily the accuracy of the measurements.
This fifteen minute activity may prevent a great deal of inaccuracy for future data collection. Try it.
