Day 7: How is Paper Recycled?
1) Video: Yesterday we learned about milk cartons that are also made from paper, today we are learning about the paper cycle for newspaper. Here is a 5 min video about the paper cycle.
2) Math: How many sheets of paper can be made from one tree?
To answer lets take a regular pine tree about 1 ft diameter about 60 ft tall that weighs about 1610 lbs. We know that in manufacturing paper, the wood is turned into pulp. The yield is about 50 percent — about half of the tree is knots, lignin (Def: a complex organic polymer deposited in the cell walls of many plants, making them rigid and woody) and other stuff that is no good for paper. So that means a pine tree yields about 805 pounds of paper. A pack of printer paper weighs about 5 pounds and contains 500 sheets (you often see paper described as “20-pound stock” or “24-pound stock” — that is the weight of 500 sheets of 17″ x 22″ paper). So, using these measurements, a tree would produce 161 packs of printer paper.
3) Social Studies: What is the typical paper consumption per person in the US? The average per person per year consumption is 712 lbs. So a little bit less then 1 tree per person per year.
Think about it: Is that a lot? How long does it take for a tree to grow 60 ft tall? Depending on the climate it takes between 35 – 50 years for a pine to grow to 60 ft.
4) ELA: A normal school with 600 students uses 2000 sheets of paper every day. How many sheets is that per month? How many packages of 500 sheets is that per year?
What can we do to make a difference?