# Yoruba numerals

According to Lounge,[1] the Yoruba language has a rather elaborate vigesimal (base-20) numeral system that involves both addition and subtraction and multiplication.

The base of the counting system is ogún 'twenty' (or 'score'). There are words for each of the decades; units in 1–4 are created by adding to these, while units in 5–9 are created by subtracting from the next decade. The odd decades are created by subtracting ten from the next even decade, as in Danish.

Up to 30, Yoruba has distinct forms of the numerals for counting objects, which derive from counting cowries.

Numeral Objects* Tens** Fives and tens Hundred Hundreds Thousands Myriads
1 ení, ọ̀kan oókàn 11 ọ̀kanlá, oókànlá 10+1 25 ẹ́ẹdọ́gbọ̀n 30−5 110 àádọ́fà 20×6−10 210 ẹ̀walélúɡba 200+10 1400 egbèje 200×7 8,000 ẹgbàárin 2000×4
2 èjì eéjì 12 èjìlá, eéjìlá 10+2 30 ọgbọ̀n, ọɡbọ̀n ǒ 120 ọ(gọ́)fà 20×6 300 ọ̀ọ́dúrún 400?−100 1600 ẹgbẹ̀jọ 200×8 9,000 ẹ̀ẹ́dẹ́ɡbàárùn 2000×5−1000
3 ẹ̀ta ẹẹ́ta 13 ẹ̀talá, ẹẹ́talá 10+3 35 aárùndílogójì 20×2−5 130 àádóje 20×7−10 400 irinwó 4×? 1800 ẹgbẹ̀sàn 200×9 10,000 ẹgbàárùn 2000×5
4 ẹ̀rin ẹẹ́rin 14 ẹ̀rinlá, ẹẹ́rìnlá 10+4 40 ogójì › ojì 20×2 140 o(gó)je 20×7 500 ọ̀ọ́dẹ́gbẹ̀ta › ẹ̀ẹ́dẹ́gbẹ̀ta 200×3−100 2,000 ẹgbẹ̀wá ~ ẹgbàá 200×10 16,000 ẹgbàájọ 2000×8
5 àrún aárùn 15 ẹ́ẹdógún*** 20−5 50 àádọ́ta 20×3−10 150 àádọ́jọ 20×8−10 600 ẹgbẹ̀ta 200×3 2,200 ẹgboókànlá 200×11 20,000 ẹgbàawǎ; ọkẹ́ kán 2,000×10; 1 bag
6 ẹ̀fà ẹẹ́fà 16 ẹẹ́rìndílógún 20−4 60 ọgọ́ta › ọta 20×3 160 ọ(gọ́)jọ 20×8 700 ọ̀ọ́dẹ́gbẹ̀rin › ẹ̀ẹ́dẹ́gbẹ̀rin 200×4−100 3,000 ẹgbẹ́ẹdógún 200×15 100,000 ọkẹ́ marun 5 bags
7 èje eéje 17 eétàdílógún 20−3 70 àádọ́rin 20×4−10 170 àádọ́sán 20×9−10 800 ẹgbẹ̀rin 200×4 4,000 ẹgbàajì 2,000×2 1,000,000 àádọ́ta ọkẹ́; ẹgbẹ̀ẹgbẹ̀rún 50 bags; 1000×1000
8 ẹ̀jọ ẹẹ́jọ 18 eéjìdílógún 20−2 80 ọgọ́rin › ọrin 20×4 180 ọ(gọ́)sàn 20×9 900 ẹ̀ẹ́dẹ́gbẹ̀rún 200×5−100 5,000 ẹgbẹ́ẹdọ́gbọ̀n 200×25 2,000,000 ọgọ́rùn ọkẹ́, ọrún ọkẹ́ 100 bags
9 ẹ̀sán ẹẹ́sàn 19 oókàndílógún 20−1 90 àádọ́rùn 20×5−10 190 ẹ̀wadilúɡba 200−10 1000 ẹgbẹ̀rún 200×5 6,000 ẹgbàáta 2000×3
10 ẹ̀wá ẹẹ́wàá 20 ogún, okòó 100 ọgọ́rùn › ọrún 20×5 200 igba, igbéo —**** 1200 ẹgbẹ̀fà 200×6 7,000 ẹ̀ẹ́dẹ́ɡbarin 2000×4−1000
* Oókàn is a contraction of owó ọ̀kan 'one cowrie'; 2–10, 20, and 30 are analogous.
** is a contraction of lé ẹ̀wá 'and ten'.
*** Ẹ́ẹdógún is a contraction of aárùndí(n)(l)ogún 'five from twenty'.
*** igbéo is a contraction of igba owó 'a heap of cowries'.

Ogún is the basic word for twenty, okòó the word when counting objects. For thirty, the forms are ọgbọ̀n and ọɡbọ̀n ǒ. Units apart from the fives are generally transparent: oókànlélógún 'twenty-one', eéjìdínlọ́ɡbọ̀n 'twenty-eight', etc. There are also more recent decimal forms for the thousands: 2,000 ẹgbẹ̀rún méjì 'thousand twice', 3,000 ẹgbẹ̀rún mẹ́ta 'thousand thrice', etc., as well as additive forms for the fives, due to the influence of English. Numbers higher than 20,000 also tend to be transparent: 40,000 is ẹgbaawa lonan meji '20,000 two times'.

## Notes

1. ^ Lounge, 2009.

## References

• Esiri, Ejiro. (2011). Numeral System of Yoruba: Focus on the Dialect of Oyo B.A Dissertation.
• Lounge, Olu. (2009). "A Vigesimal Number System".BookBuilders
• Lounge, Olu. (2009). "A Decimal Number System". BookBuilders