In our study we learned that red tides were actually areas where there was a buildup (or bloom) of microscopic algae, and that when too many of a certain type of algae formed in an area they produced a toxin that affected the fish and wildlife around them. In order to figure out just how toxic an algal bloom is you need to measure the micrograms of toxin per kilogram of victim. This requires the metric system.
The study has a great way to teach the comparison between a gram, kilogram and milligram. However, since Gess had no experience with the metric system we paused at the study when it said:
The metric system uses three families of measurement: 1Since this was Gess' first experience with the metric system I needed to make sure she understood this before we moved on. Having a child with special needs who is a visual learner I ran on over to Openclipart and grabbed some images of a ruler, a scale and a liter bottle. From there I made cards for each unit and put magnets on the back. I then explained again what each unit does.The Meter Family measures how long something is.
The Gram Family measures how heavy something is.
The Liter Family measures how much space something takes up.
After Gess got to see this concept, I went and had her label each form of measurement with the proper unit.
When she was able to do this successfully (which did not take very long) we then used each unit to measure something. We measured 200ml of water as if we needed it for a recipe. We also found that a serving of cheerios was 41 grams and her picture was 18cm long which will help us when looking for a frame.
Then I asked what unit would we use to measure a toxin? We discovered it would be the gram family.
Next we talked about the common forms of measurement within the gram family. At this point we were back in The Curiosity Files following the guide. I loved how hands on the explanation was about the difference between a kilogram, gram and milligram.
To demonstrate the difference between the gram and his "big brother" the kilogram they had you compare a dime which weighs approximately 1 gram with 2 pounds of butter which weighs close to 1 kilogram (This is what 1,000 dimes would weigh!). You then had to feel the difference by holding a dime in one hand and the butter in the other. (We had margarine so went with that.)
She could definitely tell that the kilogram was much heavier than the gram. To demonstrate how much smaller one of "gram's little brothers" the milligram was they had you use salt. What you did was pour salt on a dark colored sheet of construction paper and then get rid of all grains of salt except for 10 of them. That was not easy to do! Here is what it looks like.
That is about 1,000 times smaller than a dime! What a great visual and hands on way to grasp the concept of what size these measurements are. Here is how they all stood up together.
Then they go on to use examples of how nutrients are measured in grams. To do that we look at the nutrition label on a pack of crackers. We found how many grams of fat, protein and carbs were in a serving.
From there you find the amount of calcium that is in a serving of milk and then figure out how much calcium your body needs by measuring your weight in kilograms. At this point I felt it was beyond Gess' comprehension so we stopped. I did however feel really pleased about how much Gess did learn about the metric system by doing this one unit study on Red Tides. We really liked the way they tied the math into the study and enjoyed the hands on elements of the explanations.
To tie all of this together I found a conversion practice worksheet set called Metric Mania and used this to help Gess remember which units were smaller and larger. With that we determined whether or not we would move the decimal point to the left or right. Instead of having Gess actually move the decimal point, we just wrote L if it would move the left and be larger, or R if it would move to the right and be smaller.
And of course we started learning that "King Henry Doesn't Usually Drink Chocolate Milk" but we did not really put that into practice all that much!