Numerical place switching

Multi-constituent numerals involve a decision as to whether the lower value should precede or follow the higher value. While most languages go for consistent ordering, a minority of languages use both orders in the range from ‘11’ to ‘99’ (compare English seven-teen [unit-ten order] to seventy-two [ten-unit order]). This study presents a typological analysis of 258 inconsistent-order languages. Most, but not all inconsistent languages switch from unit-ten to ten-unit order. Numeral 20 is by far the most preferred switch point. A combination of natural order, the frequent-before-infrequent principle, paradigm consistency and the internal structure of numeral systems can account for the empirical results. The frequent-before-infrequent bias facilitates the emergence of the unit-ten order. Because the frequency of numerals decreases with increasing numerical magnitude, the frequency bias gradually loses its force, thereby enabling the natural order to take over and bringing about the switch from the unit-ten to the ten-unit order.