8th grade math presentation (1)

1.

Number and
Calculation

2.

3.

4.

5.

6.

Irrational Numbers

7.

• Integers are whole numbers.
For example, 13, −26 and 100 004 are
integers.

8.

• You can write rational numbers as fractions.
3
4
5
9 , −3 , 18
are rational numbers.
4
15
11
• You can write any fraction as a decimal.
3
4
5
9 = 9.75 , −3 = −3.266666 … , 8 = 18.454545 …
4
15
11

9.

The fraction either terminates (for example,
9.75) or it has recurring digits (for example,
3.266666666666... and 18.45454545454...).

10.

Numbers that are not rational are called irrational
3
numbers. 7, 23, 10 and
3
45 are irrational numbers.
Irrational numbers that are square roots or cube roots are
called surds.

11.

Example 1.1

12.

13.

Exercise 1.1

14.

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17.

Standard Form

18.

• The average distance to the Sun is 149 600 000 km = 1.496 ×
108 km.
• This is called standard form. You write a number in standard
form as