# Numbers

Numbers are an integral part of our everyday lives, right from the number of hours we sleep at night to the number of rounds we run around the racing track and much more. In math, numbers can be even and odd numbers, prime and composite numbers, decimals, fractions, rational and irrational numbers, natural numbers, integers, real numbers, rational numbers, irrational numbers, and whole numbers. In this chapter, we'll get an introduction to the different types of numbers and to all the concepts related to it.

Numbers form the basis of mathematics. We should befriend numbers in order to understand maths. Numbers are of various kinds. We have a long list that includes ordinal numbers, consecutive numbers, odd numbers, even numbers, natural numbers, whole numbers, integers, real numbers, rational numbers, irrational numbers, and complex numbers.

Along with numbers, we come across the interesting world of factors and multiples. This world includes prime numbers, composite numbers, coprime numbers, perfect numbers (yes, numbers could be perfect!) HCF, LCM, and prime factorization.

Building pre-number math skills is a prerequisite to understanding numbers. Pre-number skills like matching, sorting, classifying, ordering, and comparing will set the stage to build a strong number sense. Pre-number Math skills are built-in preschool years. Kids learn how to stand before they start taking small steps. In the same way, the pre number concept is very important for them to start understanding Mathematics. In this section, we will cover the different pre-number concepts like Matching and Sorting, Comparing and Ordering, Classification, and Shapes and patterns.

Number names are used to represent numbers in an alphabetical format. A specific word is used to refer to each number. To write a number in words in English, you should know the place value of each digit in the number.

The rules of PEMDAS outline the order of the operations and give structure to nested operations. In mathematics, PEMDAS is an acronym that stands for P- Parentheses, E- Exponents, M- Multiplication, D- Division, A- Addition, and S- Subtraction.

**Number Systems**

The decimal number system is the most commonly used number system. The digits 0 to 9 used to represent numbers. A digit in any given number has a place value. The decimal number system is the standard system for denoting integers and non-integers. We will be using the decimal number system for representation of Numbers up to 2-Digits, Numbers up to 3-Digits, Numbers up to 4-Digits, Numbers up to 5-Digits, Numbers up to 6-Digits, Numbers up to 7-Digits, Numbers up to 8-Digits, Numbers up to 9-Digits and Numbers up to 10-Digits.

**Cardinal Numbers and Ordinal Numbers**

A **cardinal number** is a **number** that denotes the count of any object. Any natural **number** such as 1, 2, 3, etc., is referred to as a **cardinal number**, whereas, an **ordinal number** is a **number** that denotes the position or place of an object. For example, 1st, 2nd, 3rd, 4th, 5th, etc. It indicates the order of things or objects, such as first, second, third, fourth, and so on.