Page 2

Mathematics 9 Unit 4 Lesson 1

Unit 4: Rational Numbers

 
Explore
 

The movement of Canadians from rural to urban areas has been increasing over the past one hundred years. In the nineteenth century, more Canadians lived in rural areas. Today, more Canadians live in urban areas.

 

Building Understanding
 

As you read the information about rural and urban population change on page 46 of your textbook, consider the following question: What do the positive and negative signs in the table represent?

 

The use of rational numbers gives a clearer picture of how each population is changing. The positive signs in front of the numbers represent an increase in population. A decrease in population is shown by placing a negative sign in front of the number.

 

Recall that a rational number is any number that can be put into the form , where a and b are integers and b cannot be equal to zero. Any number that can be written as a terminating or repeating decimal is classified as a rational number.

 

For more information about terminating decimals, go to Terminating Decimal in the Mathematics Glossary. For more information about repeating decimals, go to Repeating Decimal in the Mathematics Glossary.

 

Rational numbers are part of the number system. Go to Rational Numbers in the Mathematics Glossary to review the types of numbers that make up the number system. Try the demonstration applet at the bottom of the page. Move the cursor over each rectangle to see the numbers in that set.

 

Add information about number systems to your Math 9 course folder or to your foldable. See page 44 of the textbook for detailed instructions on setting up your foldable. Be sure to include examples of numbers included in each system.

 

Try This
 

You may find working with a partner for this activity beneficial. Ask your teacher about the possibility of working with another student. Discussions may be in person or virtual.

 

TT 1. Complete questions 1 to 3 of “Explore Rational Numbers” on page 47 of your textbook. As you and your partner work through the questions, think about the following:

  • how you can identify opposite rational numbers
  • what it means when rational numbers are said to be equivalent
Math 9 Folder
 

Place your answers in your Math 9 course folder.

 

Math Chat
 

Complete “Explore Rational Numbers” questions 4 and 5 on page 47 of your textbook. Post your answers to the discussion board.

 

Respond to two other postings. Keep the following points in mind as you review the responses from other students.

  • What criteria do the students use to identify opposite rational numbers? What criteria do they use to identify equivalent rational numbers?

  • How do their predictions for urban populations compare to your predictions?

  • What did they base their predictions on (for example, a graph, a table, a guess)?

  • What was the expected change for the percent of Canadians in rural areas for the 2006 to 2016 decade?