Basic Mathematics

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This document provides a basic introduction to Mathematics. It assumes that you have no prior knowledge of mathematics. By the end of this document, you will know enough mathematics to navigate this wiki.

Sets

A set is a group with objects. Sets can contain any number of objects.

To represent sets, we draw a Shape. While we can use any shape, we will use this shape below for now.

An empty set, or a set with no objects
A set with no objects. The set has an outline to show that the set itself exists.


The image above also depicts what we call an empty set. An empty set is a set with no objects.

Recall, however, that sets are "groups with objects". To represent a set with an object inside, we draw an object inside the set.

A set with a red circle inside
A set with an object inside


In fact, sets can contain any number of objects. The image below shows a set with multiple objects in it.

A set with multiple objects inside
A set with multiple objects inside


The image above shows a set with multiple objects, but each individual object is the same. Sets do not need to contain objects that are all the same as one another. Sets may contain objects that are different from one another.


[set with objects that are different from one another]


Multiple sets can be defined at the same time. Each set may have the same or different amounts of objects inside them.


[multiple sets with objects]


Sets can even have sets inside them too! Note that the set inside is called a subset while the set containing the other set is called a superset.


[set inside another set]

Set Symbols

Instead of drawing a set with objects, we can use symbols to represent the exact same thing.

Set

The symbol for a set is surrounded by an opening bracket ({) and a closing bracket (}). Each object in the set is separated by a comma (,).

Empty Set

Represented with ∅ or { }.

Equals

Equals means two sets have the same number of objects

Numbers

A number is a symbol describing the quantity of a set. In other words, a number describes the number of objects in a set.

Arabic Numerals

Place Values

Number Line

An alternative way of viewing total number of objects in a set

Arithmetic

Arithmetic lets you perform operations on numbers.

Addition

Subtraction

Multiplication

Division

Modulo

Modulo is similar to division. However, it gives you the remainder.

Ordering

This section goes over ordered sets

Ordered Sets

Ordinal Numbers

Ordinal Numbers 0-20
Number English Word Equivalent
0 Zeroth
1 First
2 Second
3 Third
4 Fourth
5 Fifth
6 Sixth
7 Seventh
8 Eigth
9 Ninth
10 Tenth
11 Eleventh
12 Twelfth
13 Thirteenth
14 Fourteenth
15 Fifteenth
16 Sixteenth
17 Seventeenth
18 Eighteenth
19 Nineteenth
20 Twentieth

If the number is greater than 20, look at the last digit. That will determine its suffix.

Ordinal Numbers Greater than 20
Digit Suffix
0 -th
1 -st
2 -nd
3 -rd
4 -th
5 -th
6 -th
7 -th
8 -th
9 -th

Axioms

An axiom is a statement that is a universally recognized truth. That is, there is no need to prove that it is true. Rather, it is true, and there is no need to prove it.