The set of **Natural** numbers is denoted by **ℕ** and consists of {1, 2, 3, ..., ∞}

The set of**Whole** numbers is denoted by **W** and consists of {0, 1, 2, 3, ..., ∞}

The set of Whole numbers and their additive inverses forms the set of**Integers** denoted by **ℤ** and consisting of {-∞, ..., -3, -2, -1, 0, 1, 2, 3, ..., ∞}

Any number that can be expressed as $x/y$ where $y≠0$, is called a**Rational** number. This set of numbers is denoted by **ℚ**

Any non-repeating, non-terminating decimal number or fraction, or transcendental number belongs to the set of**Irrational** numbers.

The set of all rational and irrational numbers forms the set of**Real** numbers. This set is denoted by **ℜ**

All positive numbers have square roots defined in the set of real numbers.

The rest of the sets of numbers below are not tested in the**GRE, GMAT or SAT**, but are included here for completeness.

A set of**Imaginary** numbers is defined that includes the square roots of negative numbers.

A number that has both real and imaginary parts is called a**Complex** number. The set of Complex numbers is denoted by **ℂ**

**Notes**:

**Additive inverses** are numbers which when added to a number give a result of 0.

e.g. $3+(-3)=0$, so $3$ and $-3$ are the additive inverses of each other.

This is similar in concept to a**multiplicative inverse (reciprocal)**, which is a number when multiplied with a given number gives a result of 1.

e.g. $3*(1/3)=1$, so $3$ and $1/3$ are multiplicative inverses of each other.

The line of numbers extending from -∞ to ∞ is called**the number line**.

Two perpendicular number lines in a plane define the normal x-y coordinate system we are used to seeing.

The vertical line is called the**y-axis** while the horizontal one is called the **x-axis**.

Every point in the plane can be identified by a pair of numbers (called**coordinates**) denoting its position along the x and y axes.

A coordinate plane where the y axis denotes only imaginary numbers while the x axis counts real numbers, is called the**Argand Diagram**.

The Argand Diagram can denote Complex numbers in that plane.

The set of

The set of Whole numbers and their additive inverses forms the set of

Any number that can be expressed as $x/y$ where $y≠0$, is called a

Any non-repeating, non-terminating decimal number or fraction, or transcendental number belongs to the set of

The set of all rational and irrational numbers forms the set of

All positive numbers have square roots defined in the set of real numbers.

The rest of the sets of numbers below are not tested in the

A set of

A number that has both real and imaginary parts is called a

e.g. $3+(-3)=0$, so $3$ and $-3$ are the additive inverses of each other.

This is similar in concept to a

e.g. $3*(1/3)=1$, so $3$ and $1/3$ are multiplicative inverses of each other.

The line of numbers extending from -∞ to ∞ is called

Two perpendicular number lines in a plane define the normal x-y coordinate system we are used to seeing.

The vertical line is called the

Every point in the plane can be identified by a pair of numbers (called

A coordinate plane where the y axis denotes only imaginary numbers while the x axis counts real numbers, is called the

The Argand Diagram can denote Complex numbers in that plane.

By continuing to use this website, you acknowledge that this service is provided as is, with no warranty of any kind whatsoever.

Copyright 2015 ChiPrime. All rights reserved.