Answer:
A numeral system is a writing system for expressing numbers; that is, a mathematical notation for representing numbers of a given set, using digits or other symbols in a consistent manner. The same sequence of symbols may represent different numbers in different numeral systems.
Explanation:
Different types:
Oksapmin, base-27 body part counting. Photo Courtesy of Austronesian Counting. ... 
Tzotzil, base-20 body part counting. ... 
Yoruba, base-20 with subtraction. ... 
Traditional Welsh, base-20 with a pivot at 15. ... 
Alamblak, numbers built from 1, 2, 5, and 20. ... 
Ndom, base-6. ... 
Huli, base-15. ... 
Bukiyip, base-3 and base-4 together.