Mathematics 7

# Web Quests

## WORKING ON WASTE AT SCHOOL

The focus of Chapter 4 of Nelson Mathematics 7 is Patterns and Relationships. The vermicomposting program context of this Web Quest provides your child with a realistic context for modelling and making predictions based on patterns. The Web Quest also allows your child to practice his or her research skills and learn more about environmentally friendly programs.

### GOALS

• Recognize, extend, and create patterns.
• Use a table of values to represent a sequence and solve a problem.
• Use a scatter plot to represent a sequence and make predictions.
• Clearly describe the steps followed to reach a solution to a problem

grid paper

a ruler

coloured pencils

a calculator

### VOCABULARY

Your child should be familiar with the following vocabulary:

sequence - a list of things that are in logical order or follow a predictable pattern or example (e.g., the sequence 1, 3, 5, 7, 9, . shows the odd numbers in order)

term - each number or item in a sequence (e.g., in the sequence 1, 3, 5, 7, ., the third term is 5)

table of values - an orderly arrangement of facts set out for easy reference

scatter plot - a graph that attempts to show a relationship between two variables by means of points plotted on a coordinate grid

coordinates - an ordered pair, used to describe a location on a grid labeled with an x-axis and a y-axis

### INTRODUCTION

There are many different ways to take care of and protect the environment. What are some of the things you can do to preserve and protect the environment at home and at school?

NOTES FOR PARENTS:

* Before each Internet session, it is always a good idea to check links to ensure they are still active.

Together, read the Introduction. Brainstorm the different ways to protect the environment, such as recycling glass and paper, eliminating or reducing packaging, re-using objects, and cutting down on consumption. If your child does not offer composting as an example, ask him or her if he or she is familiar with it, and if not, describe what it entails.

Your class has been chosen to be the start-up class for a vermicomposting program at your school. Vermicomposting means composting with worms.

The principal of your school would like your class to do some Internet research on the subject and make a presentation using the data you find. You will need to find out the following:

• general information on vermicomposting
• the quantity of worms and bins you would need for one classroom
• the number of classrooms that will be vermicomposting after one year
• the amount of castings your worms will have produced after 36 weeks and after 90 weeks

Together, read through the Task section. Ensure that your child is clear on what is expected of him or her.

1. Use the Web links below to research and write a brief report on one of the following aspects of vermicomposting. Then present your report to the class.
1. possible building materials for bins
2. types of bedding material and the quantity needed
3. what foods to feed your worms
4. feeding techniques
5. harvesting the compost
6. possible problems and how to solve them

Click on the following links to find out more about vermicomposting. Consult at least three sites for your research.

SWRC -- Vermicompostin

Compost Action Project: Vermicomposting

Featured Themes - Waste

Composting with Worms

TIP: When you are looking for specific information on a Web page, scan the text instead of reading all of it from start to finish. To begin, do not read every word of the texts but look through them quickly. For example, if you are looking for information on what to feed worms, look at the section headings first and focus on sections that are related to this subject, such as a section titled “Feeding Worms”.

QUESTION 1

Ask your child to focus on one of the six areas to research. Stress that he or she should also have a general understanding of vermicomposting but only need to prepare a short report on the specific point.

Summary of information on Web sites:

• SWRC -- Vermicomposting
Provides basic info, including bin size and worm chart using kg and cm.
• Compost Action Project: Vermicomposting
Provides basic information, including number of worms in half a pound.
• Featured Themes - Waste
Provides basic information, including diagrams. Source for fact that worms are mature at 2 months.
• Composting with Worms
Less accessible. Encourage your child to scan only for relevant information. Source for fact that worms double in number after 2 months.

Encourage your child to use the scan technique. Much of the information in these Web sites is repetitive and does not need to be read thoroughly.

1. Use the information on the Web sites to decide on the number of bins and the quantity of worms (in kg) you will need for your class. Be sure to include the size of the bins in your answer. Explain your thinking and show all your work.

Keep the following in mind when making your decision:
You will be creating waste from only one meal a day and snacks, five days a week. So divide the number of people in your class by 2 since you will be producing about half as much waste as an average person.

Some students will need to volunteer to take care of the worms at their homes over the holidays and the summer. This means the bins need to be appropriate for an average-sized family.

QUESTION 2

Your child should be able to recognize the benefits of having several smaller boxes opposed to one or more large boxes in the classroom.

It will be easier for someone to take the box home over the holidays and have enough food to feed them. If we have troubles with one box we will still have others to use and we won’t be risking all our worms. If we have smaller boxes they will probably take up less room than one box.

All the Web sites provide information on the size of box needed based on the food consumption of a family. Your child should be able to recognize that his or her class would be producing less waste because they only eat one meal at school and no cooking waste would be going in the box.

Sample question:

“What are some of the advantages of using several smaller boxes in the classroom?”

We know that:

• There are 30 students in the class
• We eat only one meal plus snacks and are not there over the weekend
• The boxes must be a convenient size for students to take home over the holiday.

We have chosen to have 3 boxes that are designed to be used by 4-6 people because I think this is the size of many families so they will be easy to use over the holidays, and that they are not too big for our classroom. We decided to have three boxes because we predicted that we would be producing about half the average amount of waste because we eat only one meal at school five days a week. We divided the number of students in half, which is fifteen, because it would be more likely we will be producing the waste of 15 people. The boxes are for 4-6 people and five divides easily into fifteen, giving a factor of 3, so we will need 3 boxes.

We will need 6 kilograms of worms.
We know that for a bin for 4-6 people you need between 1.5 and 2 kilograms. We have decided to use the maximum amount of worms in our bins, and since we will have 3 bins we will need 6 kilograms of worms to begin vermicomposting.

1. Worms reproduce at a rapid rate, which is good news because the more worms you have, the more classes you can get vermicomposting.
1. Using the information below, decide how many bins you could set up after one school year (from September to June).
• Worms are able to reproduce at two months old.
• Worms double in number every two months.
• When you have double the number of worms, you need double the number of bins
1. Complete the table of values to display your results.
2. Write the rule for the pattern.
3. How many classrooms will this number of bins supply?

QUESTION 3

For extra challenge:

Have your child extend his or her pattern further.

Sample questions:
“How are patterns useful in helping you solve these problems?”
Patterns help me create organized lists, make predictions and generalizations and can save me time when making calculations.

“What is a sequence?”
A sequence is a list of items in a logical order or that follow a pattern.

 Term Number Month Number of Bins 1 September/October 3 2 November/December 6 3 January/February 12 4 March/April 24 5 May/June 48

The pattern rule for the sequence is multiply the number by two each time.

1. The castings that the worms produce can be used as fertilizer. 450-600 worms can produce 18 litres of castings in 9 weeks.
1. Click on this link Compost Action Project: Vermicomposting to find out how many worms are in a half a pound.
2. How many litres of castings can 1 pound of worms produce? How many pounds of worms does your class have?
3. Complete the table of values to show the minimum amount of castings your worms could produce in 36 weeks.
4. Write a pattern rule for the number sequence in the table.
5. Write the next four terms in the sequence.
6. Create a scatter plot to predict the minimum amount of castings your worms could produce in 90 weeks.

QUESTION 4

This question requires your child to find two pieces of information found on two of the Web sites to solve the problem.
Your child will be working with an imperial measurement, as it is the only way the information is provided in the Web resources.
Because this question involves several steps, your child may benefit from using the scaffolding, which will guide him or her through the initial steps of the problem.

Sample questions:
“How do you use a scatter plot to make predictions?”
You look at how the coordinates are placed on the graph and determine if there is a pattern. If there is a pattern then you can extend the pattern to make predictions.

“Why do the coordinates in a scatter plot form a line?”
Because the numbers we are using are in a sequence.

For extra support:
Provide your child with scaffolding for Step 4.

For extra challenge:
Have your child decide on a size and price for a bag of compost and have him or her calculate how much money his or her class could generate from the sale of their worms’ fertilizer of __ years/months.

Sample questions:
“Do you think there is another strategy for solving this problem?”

“Did you make a plan before you started to make your calculations?”