Yorùbá is a vigesimal (base 20 system) that incorporates mathematical operations such as multiplication, addition and subtraction in the regular names of individual numbers. As such the word for 20, for example is two twenties ogójì. Yorùbá is Ama’s L3 and she is becoming proficient in learning how the base 20 system offers a different way of thinking about equations from the base 10 system invented by Afrikans some 30,000 years ago and to which she has been exposed in Akan (Twi) and english.