How Much Do The Leaves on a Tree Weigh?

Purpose:	To improve estimation skills
Season:	Leaf bearing season
Materials:	Tree, scales or balance for measuring small weight or mass, pencils and paper.
TEKS:	3.2 A thru E 3.3A,C
Procedure:	Collect enough leaves from the tree so that they will show a significant amount on the scales or balance. Divide the weight or mass by the number of leaves being weighed to find the weight or mass of an average leaf.
	To find the estimated weight of all the leaves on a tree, figure the estimated number of leaves on the tree using the method from "How many leaves on a tree?". Multiply that number by the average weight per leaf for the total weight of the leaves on the tree.
	To calculate how much of the weight or mass of a leaf is water, do the following: determine the weight or mass of an average fresh green leaf and put the leaves you used to do this in a paper sack. Keep these leaves in the paper sack and dry then for several days in a warm dry place (a closed, parked car in sunny weather for several days or for several hours in an oven at 100°F to 120°F). After they are dried, determine the average weight or mass of the leaf using the same method you use previously. Subtract the average weight or mass of the dried leaf from the average weight or mass of the fresh leaf. This will give you the average weight or mass of the fresh leaf and multiply by 100 to determine the percent water.
	The results of this activity may be used as a lead in to why it is better to compost leaves rather than send them to the solid waste disposal facilities (city dump).
Questions:	How could you calculate the weight (mass) of one leaf? How can you determine the amount of moisture in a leaf? Can you explain a better way to get these answers?