Berry Mass Comparison

We are currently studying mass and all it encompasses. Students have learned to find the mass of various objects and have been comparing items using terms lighter than or heavier than. Upon considering ideas of how to incorprate FNMI content into this unit, I recalled a conversation I'd had with Tammy Taypotat earlier in the school year. When discussing various ideas she has done in the classroom and brainstorming different lesson ideas, she had mentioned finding the mass of berries.

Berries were a food staple for many FNMI groups. They grew in the wild throughout the country and could be harvested for sustenance.  

To incorporate this into the classroom, I decided to have students find the mass of dried berries and their fresh counterparts and then compare them (using terms heavier and lighter).  I was able to find certain dried fruits at Bulk Barn and then hunted down their fresh counterparts at Superstore and Wal-Mart. I was able to find the following berries:

Raspberries

Blueberries

Strawberries

Cranberries

(Warning: dried fruit can be VERY pricey).

To start, students made predictions as to which they thought was heavier for each type of berry: dried or fresh.  Next, we took a 1/2 cup of one type of fresh berry and found its mass using a balance and weights. Once the balance was even, I orally noted the various gram measures we used as students wrote them down on scrap paper and added them together to find the mass.  This was a great way to practice counting on, mental math and counting by 25s (we made math connections to money).

We noted this mass in our chart on the board (see pic below). Next, we found the mass of its dried counterpart and recorded it next to its fresh form.  We then made comparisons based on the masses - ie. Which one was heavier? Lighter?  What was the difference between the masses? 

Overall, students noted from the data collected that the dried forms of fruits weighed more than the fresh.  They further took the lesson to infer why this may be.  Some suggestions were: the fresh fruit didn't fill in the measuring cup (there were some gaps between the berries), there is water and air filling up the fresh berries which may make them lighter, etc.

At the end, students found ways to further extend this lesson:

1) Compare one fresh berry to one dried berry (of the same kind)

2) Soak the dried berries in water to see if they retain the water

3) Weigh dried berries soaked in water to dried berries in regular form (of the same kind) to see if there is a difference in mass

The students really enjoyed this lesson and with their inquiry have managed to extend it into tomorrow's dayplan. :)