https://www.youtube.com/watch?v=qevpRffg6wc

The Sumerians represented one as a token. You could take away and add tokens but cannot take away marks on bones. (Arithmetic) The Sumerians lived in cities and they needed to organize things so they used maths to work out what amount of each thing a person got, collect taxes and calculate profit, loss and wealth. They started to make marks on clay to keep permanent records and their system soon became very complex.

The Egyptians turned one into a measuring unit. The cubit which equaled a person's arm length plus the width of their palm. The Egyptians made a stick so the workers making the pyramids would understand what one equaled. They used different drawings for different numbers. 1 was a line, 10 was a rope, 100 was a coil and 1000 was a lotus. The Egyptians also used one million.

Pythagoras came up with the idea of even and odd numbers. He was convinced that everything in the universe was made up of whole numbers, including music. He tried to make right angled triangles have sides of equal units but it didn't work and he gave up. Archimedes loved games and he tried to find out things like how many grains of sand would fit into the universe. Archimedes was killed by a roman soldier.

The Indians created numerals for each of the numbers from 1 till 9. The Indians also created the number 0, nothing. The new number that the Indians created, 0, could make numbers super big or super small. The Indians also tried calculating the diameter of the globe and they were less than 1% off.

The Romans used one to be a numerical grid for their army. Ten soldiers were called a section and a hundred soldiers were called a century. The Romans used new symbols to represent their numbers such as I which equaled one, IV which equaled 4 and C which equaled one hundred. When the Romans did maths, they had to use an accounting board, they didn't use the symbols. It took a very long time to write down numbers using the Roman numerals as they were complicated.

The people in Baghdad could now do more complicated things in maths like algebra and equations.

Fibonacci was interested in the arabic numbers and wrote a book called "The Book Of Calculations" which was basically a showcase of the arabic numbers. However, many people didn't want to use the new numbers. People in Italy had different currencies in most of the cities and you had to change currencies if you went to visit another city. To exchange the money, you had to go to a money exchange bench or bank. Some of the people who exchanged the currencies used the old system which was using an abacus but instead of beads, you used counters in which you could see what the exchanger was doing but the other people used the new Indian numbers. People couldn't understand what the Indian numbers were so they couldn't check if the exchanger was cheating them or not. Soon, some cities in Italy banned using the new numerals. For example, in 1299 BC, the city of Florence banned the use of the new numerals.

Gottfried Wilhelm Leibniz tried and succeeded in creating a working calculator because he was convinced that he could rid humans of error. He was also convinced that 1 and 0 were the only numbers that anyone needed so he invented a system using only 1's and 0's called the binary system. Machines also use binary because it's easy for them to process.

Colossus was the world's first working binary computer/machine. Colossus was electronic and everything ran one 1's and 0's. Things in this world are also made up of 1's and 0's like barcodes, bank statements and medical records.