1. It is said that as early as 4,500 years ago, our ancestors used scribed lines to measure time.

Rudolph, a Dutch mathematician, measured the 35th place of pi.

As early as more than 2000 years ago, our ancestors made a directional instrument with magnets. This instrument is Sina.

4. China is the first country to use the rounding method to complete the calculation.

5. German mathematician kravis was the first to use points as decimal points.

6. Digital system. Digital system is a way to deal with "how much". Different cultures have adopted different methods in different times, from the basic "1, 2,3, many" to the highly complex decimal notation used today.