Number Line

A number line demonstrates the relationship of a number when referenced to zero. Positive numbers are to the right of zero, and negative numbers are to the left of zero.

Number Definitions

An Integer is a number that is not a fraction or decimal (1, 2, -3, -100)

• A whole number is an integer that is positive (1, 2, 3, 100)

A real number is a number that can be expressed as a fraction or a decimal (1.0, 2.11, 100.4036)

• A rational number is a number that can be expressed as a ratio between two 2 integers (0.2, 1/5, 1.0)
• A irrational number is a number that cannot be expressed as a ratio between 2 integers (π, e, √10 ) 

Inequalities

An inequality is the relationship between two or more integers

Example:

2 > 1 (two is greater than 1)

2 < 3 (two is less than 3)

Inequality symbols (where A and B are integers)

Absolute Value

The absolute value is the distance the number is away from zero on a number line. It does not matter if it is positive or negative. Taking the absolute value of a number gets rid of any negative sign

Example:

| -5 | = 5

| 5 | = 5

But if the negative sign is outside of the absolute value, then the number remains negative

– | 5 | = -5

Places

All numbers have “places” to indicate their magnitude