- Worked Examples and Thinking Time Solution
- Practice Now(Solutions)
- Exercise 2A (Solutions)
- Exercise 2B (Solutions)
- Exercise 2C (Solutions)
- Exercise 2D (Solutions)
- Review Exercise 2(Solutions)
- Challenge Yourself 2 (Solutions)

__Section 2.1: Negative Numbers__

The negative number –2 as negative 2, not minus 2 (‘negative’ is a state while ‘minus’ is an operation). For example, if you have $5 and you owe your friend $2, how much do you have left? Since nothing is mentioned about you returning money to your friend, you have $5 left. Thus $2 is a state of owing money. However, if you return $2 to your friend, you have $5 + (–$2) = $5 – $2 = $3 left, i.e. 5 minus 2 is an operation of returning money.

__Section 2.2: Addition and Subtraction involving Negative Numbers__

Key Concept 1: Adding a negative number is the same as subtracting the absolute value of the number,

e.g. 5 + (−2) = 5 − 2.

Key Concept 2: Subtracting a negative number is the same as adding the absolute value of the number,

e.g. 5 − (−2) = 5 + 2.

__Section 2.3: Multiplication and Division involving Negative Numbers__

We will start by trying to work out the answer to **7 × (-4)**.

First of all, think about the sum **7 × 4**. The answer is 28.

This is the same as **7+7+7+7**, which gives **28**.

In the same way, the sum **7 × (-4)** can be written **(-7) + (-7) + (-7) + (-7)**, which gives **-28**.

__Section 2.4: Rational Numbers and Real Numbers__

Traditionally, real numbers are classified as either rational or irrational numbers. Another way to classify real numbers is according to whether their decimal forms are terminating, recurring, or non-recurring (see page 50 of the textbook).