据汉代徐岳所著《数术记遗》和《数理精蕴》记载,古代命数法分为三等:「下数十十变之」(如十百为千,十千为万),「中数万万变之」(如万万为亿」;「上数数穷则变」,又称:数凡十等,为亿、兆、京、垓、秭、壤、沟、涧、正、载。因此,据「上数」变法,则一亿亿称为兆,一兆兆称为京…… According to the records of “Number Shu Ji Ji Ji” and “Mathematical Jing Yun” written by Xu Yue in the Han Dynasty, the ancient law of life was divided into three categories: “dozens of changes in the next” (such as ten thousand for thousands, ten thousand for ten thousand), “ In the tens of thousands of changes ”(such as the million for the million“; ”the number of poor change“, also known as: Number ten, etc., for the million, trillion, Beijing, 垓, 秭, soil, ditch, stream, Therefore, according to the ”last resort" method, one hundred million is called trillion, one trillion is called Beijing ......