The following practices are aimed at soil conservation except

Yoruba counting is vigesimal (base-20). Basic numbers: ọkan (1), eji (2), ẹta (3), ẹrin (4), arun (5). Numbers 11-14 add to 10: “ọkanla” = 10+1. Numbers 15-19 subtract from 20.

This system differs from English. “Ẹẹdọgbọn” (25) means 30-5. “Ogoji” (40) is 20×2. Large numbers combine multiplication, addition, and subtraction in complex ways.

While many Yoruba speakers now use English numbers for convenience, traditional counting remains important culturally and appears in proverbs, songs, and ceremonies.