Book excerpt: The papers in this collection present the numeral systems of more than twenty Nigerian languages. The papers mainly emanate from a workshop on the numeral systems of Nigerian languages organised by the Linguistic Association of Nigeria during its 23rd Annual Conference which was held at the University of Port Harcourt, Nigeria. The workshop arose from awareness created by Dr. Eugene S.L. Chan on the need for Nigerian linguists to document this severely endangered but very important aspect of natural languages. The quantum of mathematical computations - addition, multiplication, subtraction, or a combination of two or all of these - involved in the numeral systems of Nigerian languages is remarkable. The papers reveal that a variety of numeral systems do exist, such as: binary, decimal, incomplete decimal, duodecimal, quinary, quaternary, ternary, mixed, body-part tally systems, and much more. The book is a resource about how different languages manipulate their numeral systems.