1. Positive and Negative Numbers
Slideshow 2, Mr Richard Sasaki

2. Objectives Recall how inequalities relate to the number line
Understand the meaning of positive and negative numbers
Understanding how to use inequalities for positive and negative numbers
4 minute inequality drill! Please place inequality symbols in the right place.

3. Answers (Top Section) < > < < > < < > <

4. Answers (Bottom Section)
<
<
<
<
>
>
>
>
>
<
>
>
>
>
>
>

5. The Number Line
Let’s have another look at a number line…(well a line). 𝑥 𝑦
Which number is greater, 𝑥 or 𝑦?
𝑦 is greater than 𝑥. 𝑦
> 𝑥
We know this is true, even if no numbers are shown. (Greater numbers are always on the right of the number line.)

6. The Number Line
Let’s have a look at a number line. This time there is one number! −∞ ∞ 𝑦 𝑥
What can we say about 𝑥? 𝑥
>
What can we say about 𝑦? 𝑦
<
So 𝑦 is and
negative
𝑥 is
positive

7. Positive and Negative Numbers
Numbers greater than 0 are called numbers and numbers less than 0 are called numbers.
positive
negative −∞ ∞
Negative numbers
Positive numbers
The number 0 is not positive or negative (disputed, the French believe it is both).
However, would be positive and − would be negative.

8. Positive and Negative Numbers−∞ ∞ −7 −2
By looking at the number line, it is very easy to see which numbers are greater (or less) than other numbers.
Which is greater?
−2 is greater.
As −2 is further to the right, −2 > −7.

9. Example C B D A -∞ ∞ Find which numbers A, B, C and D represent.
A is . 2
Complete each of the statements below with an inequality symbol.
B is −4
C is
−5½
(Or − 11 2 )
A D
>
C B
<
D is −½
D B
>

10. −10 10
positive
negative
positive
negative
positive
neither/both
9 2
− 1 2 1 −4 𝑎
𝑎>𝑑 or 𝑑<𝑎 −2
− 1 2 1
5 2 4

11. 9 2
8.5
− 1 2
3 2
29 3
−7.5
>
>
>
>
<
<
>
>
>
4 is greater than −2
− 1 2 is less than 1 2
− 2 3
− 1 2
1 3
− 2 3 <− 1 2 < 1 3
𝑥= 1 2 , 𝑦=− 5 6
= = 4 3