Math is invented by an ancient Chinese king for an entirely different reason, to keep track of all his sheep. When King of Qin realized that some of them had gone astray, he decided to figure out the best way to do it. He asked his advisors what method they thought was best.
The first advisor suggested a method called “divide and multiply.” So, the king decreed that each king's shepherd should count the number of sheep in his own domain. Then, he would divide the number by the number of sheep in the domain of the next king, the count would be the number of sheep in that king's domain, and he would multiply the count by the number of sheep in the domain of the last king. Finally, the result would be the number of sheep in the whole kingdom.
This system worked well for ten years, until King Zhao started having trouble remembering which king's domain was which. So, he asked the king's advisers for a better system. They told him that they had figured out a way to divide and multiply even faster, with two fewer steps. The new system would simply multiply each king's count by the number of other kings, and then divide each result by the number of all the other kings. So, for instance, the first king's count of 6,402 would be 6,402 multiplied by 10,402 (the number of other kings), and then divided by the number of all the other kings, 50,401. That would equal 5,998,400. And the result would be 5,998,400 divided by 10,401, which equals 5,994,539.
The first advisor suggested a method called “divide and multiply.” So, the king decreed that each king's shepherd should count the number of sheep in his own domain. Then, he would divide the number by the number of sheep in the domain of the next king, the count would be the number of sheep in that king's domain, and he would multiply the count by the number of sheep in the domain of the last king. Finally, the result would be the number of sheep in the whole kingdom.
This system worked well for ten years, until King Zhao started having trouble remembering which king's domain was which. So, he asked the king's advisers for a better system. They told him that they had figured out a way to divide and multiply even faster, with two fewer steps. The new system would simply multiply each king's count by the number of other kings, and then divide each result by the number of all the other kings. So, for instance, the first king's count of 6,402 would be 6,402 multiplied by 10,402 (the number of other kings), and then divided by the number of all the other kings, 50,401. That would equal 5,998,400. And the result would be 5,998,400 divided by 10,401, which equals 5,994,539.
