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. Multiples are also very important in the numerical system for example the number 60 is ọgọ́ta which literally means three twenties (ogún = 20, ẹ̀ta = 3).

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 ẹ̀ẹ́dọ́gbọ̀n 30−5 110 àádọ́fà 20×6−10 210 ẹ̀wálélúɡba 200+10 1400 egbèje 200×7 8,000 ẹgbàarin 2000×4
2 èjì eéjì 12 èjìlá, eéjìlá 10+2 30 ọgbọ̀n, ọɡbọ̀n ǒ 120 ọ(gọ́)fà 20×6 300 ọ̀ọ́dúrún, ọ̀ọ́dúnrún 400−100 1600 ẹgbẹ̀jọ 200×8 9,000 ẹ̀ẹ́dẹ́ɡbàarùn-ún 2000×5−1000
3 ẹ̀ta ẹẹ́ta 13 ẹ̀tàlá, ẹẹ́tàlá 10+3 35 aárùn-ún-dínlógójì 20×2−5 130 àádóje 20×7−10 400 irinwó 1800 ẹgbẹ̀sán 200×9 10,000 ẹgbàarùn-ún 2000×5
4 ẹ̀rin ẹẹ́rin 14 ẹ̀rìnlá, 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 ẹgbàajọ 2000×8
5 àrún aárùn-ún 15 ẹ̀ẹ́dógún*** 20−5 50 àádọ́ta 20×3−10 150 àádọ́jọ 20×8−10 600 ẹgbẹ̀ta 200×3 2,200 ẹgbọ̀kànlá 200×11 20,000 ẹgbàawàá; ọ̀kẹ́ kan 2000×10; 1 bag
6 ẹ̀fà ẹẹ́fà 16 ẹ̀rìndínlógún, ẹẹ́rìndínlógún 20−4 60 ọgọ́ta › ọta 20×3 160 ọ(gọ́)jọ 20×8 700 ọ̀ọ́dẹ́gbẹ̀rin › ẹ̀ẹ́dẹ́gbẹ̀rin 200×4−100 3,000 ẹgbẹ̀ẹ́dógún; ẹ̀ẹ́dẹ́gbàajì 200×15; 2000x2-1000 100,000 ọ̀kẹ́ márùn-ún 5 bags
7 èje eéje 17 ẹ̀tàdínlógún, ẹẹ́tàdínlógún 20−3 70 àádọ́rin 20×4−10 170 àádọ́sàn-án 20×9−10 800 ẹgbẹ̀rin 200×4 4,000 ẹgbàajì 2000×2 1,000,000 àádọ́ta ọkẹ́; ẹgbẹẹgbẹ̀rún 50 bags; 1000×1000
8 ẹ̀jọ ẹẹ́jọ 18 èjìdínlógún, eéjìdínlógún 20−2 80 ọgọ́rin › ọrin 20×4 180 ọ(gọ́)sàn-án 20×9 900 ẹ̀ẹ́dẹ́gbẹ̀rún 200×5−100 5,000 ẹgbẹ̀ẹ́dọ́gbọ̀n; ẹ̀ẹ́dẹ́gbàata 200×25; 2000x3-1000 2,000,000 ọgọ́rùn-ún ọ̀kẹ́, ọrún ọ̀kẹ́ 100 bags
9 ẹ̀sán ẹẹ́sàn-án 19 ọ̀kàndínlógún, oókàndínlógún 20−1 90 àádọ́rùn-ún 20×5−10 190 ẹ̀wádínlúɡba, àádọ́wàá 200−10 1000 ẹgbẹ̀rún 200×5 6,000 ẹgbàata 2000×3 3,000,000 àádọ́jọ ọ̀kẹ́ 150 bags
10 ẹ̀wá ẹẹ́wàá 20 ogún, okòó 100 ọgọ́rùn-ún › ọrún 20×5 200 igba, igbéo 20x10 1200 ẹgbẹ̀fà 200×6 7,000 ẹ̀ẹ́dẹ́ɡbàarin 2000×4−1000 4,000,000 igba ọ̀kẹ́ 200 bags
* Oókàn is a contraction of owó ọ̀kan 'one cowrie'; 2–10, 20, and 30 are analogous.
** is a contraction of lé ẹ̀wá 'and ten'.
*** Ẹ̀ẹ́dógún is a contraction of aárùn-ún-dí(n)(l)ógún '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 ẹgbàawàá lọ́nà méjì '20,000 two times'.

Notes

1. ^ Lounge, 2009.

References

• Adéoyé, C L (1979). "Ìṣirò" [Counting]. Àṣà àti Ìṣe Yorùbá [Yoruba Culture and Practices] (in Yoruba). Ibadan, Nigeria: University Press PLC (published 2005). pp. 55–65. ISBN 9781540435.
• 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