#### Arrangement of Electrons Around Atomic Nucleus

Atomic orbital are areas around the nucleus where electrons are likely to be found. Electrons revolve around...

Numbers are the math objects that are used for measuring and counting. In math, the numbers are defined over the years. Such as zero (0), rational numbers, complex numbers, irrational numbers and negative numbers. The notational symbols which represent value are known as 'Numerals'.

**Let us learn numbers with the below image that shows numbers from 1 to 100:**

The History goes long back into the past to the start of historical times. Understanding of rational numbers comes before history, yet, sadly, no proof of this has survived into the present day. The first evidence is incorporated in the Historic Egyptian record the Kahun Papyrus. Historical Greeks have proven to be helpful on the **history of rational numbers** as an element of their number theory.

Rational numbers are actually the group of all ratios composed of real numbers, that do not have 0 as a denominator. Rational numbers tend to be a kind of real numbers. The group of rational numbers are denoted simply by "Q". Rational numbers contain whole numbers, natural numbers, fractions and integers.

We know these as Arabic Numerals, the **history of number system** has been modified largely through the centuries. Initially passing on to Arabs from the middle east and from there in the Middle Ages to the Europe, finally in the present the most commonly and frequently used numbers all over.

The number system which is used now a days is actually a place value (decimal System). This means that not just the number, also the way the number is placed or positioned is important.

For instance take the number 647:

This features three numbers: 6, 4 and 7. Due to the fact we make use of a system called place value, we all know that the 6 will not stand only for 6, it indicates 600. The 4 represents 40, as well as the 7, as being in the ones position, is simply 7. Instead of writing 600 + 40 + 7, our place value system permits us to write it just as 647.

Early humans used animal bones for counting animals and keep account of lunar cycles, by scientists these are known as tallying system. Although tallying system was totally different from the modern number concept, it was actually the **invention of numbers** which we use today in our daily life.

Scientists discovered the first use of place value system dates back to 3400B.C by Egyptians. The zero (0) was invented by the Indian astronomer and mathematician "Brahmagupta".

You may witness in some places the numbers are written in words. The numbers are written in words to avoid mistakes and to be accurate. Below we shall learn how to write math numbers in words format from numbers 1 to 30,

Place value number system is very helpful for writing numbers when compared to any other number systems like roman numbers for example. It is due to the usage of same digits again and again. Exact same numbers can be used for writing very small as well as large numbers.

The place value number system uses only ten digits, they are: 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. But number system used differently used in different countries.

In international number system, the comma is placed after every 3 digits from the right and each group has different names that includes Trillion, billion, million, thousand and ones.

**Let us understand international number system better with the below example:**

But in Indian number system, the comma is placed after every 2 digits from the right, except the first 3 digits and each group has different names such as- Crore, lakh, thousand and ones.

**Let us understand Indian number system better with the below example:**