Adopted on November 18 at the 27th General Conference on Weights and Measures in Versailles, France, ronna- and quetta- indicate extremely big numbers, whereas ronto- and quecto- describe extremely small numbers. The International System of Units, or SI, has not been modified since 1991, when the prefixes zetta-, yotta-, zepto-, and yocto- were introduced.
In mathematics, Ronna- is 1027 (a numeral followed by 27 zeroes) while quetta- is 1030. (30 zeroes). Their diminutive equivalents ronto- and quecto- likewise refer to 27 and 30 zeroes, respectively, although these are followed by a decimals. previously, the metric system’s range was limited to yotta- and yocto- (24 zeros).
Reference: On the extension of the range of SI prefixes. 27th meeting of the General Conference of Weights and Measures, Versailles, France, November 18, 2022.
