Today it is the Hindu-Arabic numeral system but in the Middle Ages it was the Roman numeral system.
Most people do not use it in their daily lives.
You and I use it every day, and have done all our lives.
Melvil Dewey created the Dewey Decimal system. It is a classification system used by libraries, and not what is meant in the question. The decimal number system is the number system that we all use on a daily basis; it was invented by a succession of Arab and Hindu mathematicians beginning about 1400 years ago.
It is the number system we use everyday.
The Maya number system, developed by the ancient Maya civilization, was primarily used in the region that is now Mexico, Guatemala, Belize, Honduras, and El Salvador. While it is no longer in use for daily life, the system is studied and appreciated in academic contexts, especially in archaeology and anthropology. The descendants of the Maya people in these countries may still have cultural ties to the number system through traditional practices and rituals.
Children can use multiplication in their daily lives in a number of creative ways. A child can calculate how many times they eat in a week for fun for example.
we can use music in our daily lives by setting the mood
We breathe it.
Eating
In a sale,
negotiation
temperature,money(withdrawing&depositing in a bank),and most numbers the are on a number line.
money uses decimals
money, medicine
Technology
Nowadays the whole world uses the same number system - decimal for daily use and (essentially) binary for electronic and optical data storage and processing.
Most people do not use it in their daily lives.