Soaking Seeds Part 1
Lesson 2 of 12
Objective: SWBAT Determine appropriate measurement tools and find the mass of dry means.
I posted the focus question (How could we measure the effect of water on seeds?) and had my class add that to their science notebooks. I then gave them two minutes to write down their answers. I had them share with their tables, and then gave them another minute to write their answers. I did this because I want each student to be accountable for the thinking, but I also know they benefit by discussing their ideas with each other.
I had a few students share their ideas with the class, and found that they all suggested some kind of linear measurement with a ruler or tape measure, which wasn't appropriate to the task. I asked them to think about how they could measure the amount of water absorbed, (and cued them by making a weighing motion with my hands.)
Next, I gave a quick explanation of mass vs. weight. I know it’s generally beyond their development level, but I’m sure it made sense to a few, and laid the foundation for understanding later. Then I demonstrated how to zero the balances and find the mass of an object. Finally, I reviewed the expectations we agreed upon for group work, and emphasized taking turns.
I had each table find the mass of 5 lima beans, and record their data.
After a few minutes, I called each table to chart the results of the class. I asked what possible reasons there might be for differences. They realized right away that there could be different sized beans, but also came up with variances in how students might be measuring, which is a good way to illustrate why science requires multiple trials.
I then told them we would fill up the cups with water and let them soak overnight. I asked them to write down a prediction about what the mass would be the following day, and share their predictions with their table. I recorded these from the class as well- Our Class Dry Bean Measurements and Predictions