On what number is the metric system based

The metric (or SI) system of units of measure is based on the number  10
and powers of it.

That's why people in Liberia, Burma, and the USA find it so confusing and
hard to learn, and why we stick to our familiar customary system based on
the number  3,  12,  1760,  5280,  16,  2,  4,  128, etc.

Answerwavelength;