Yotta (24 zeroes) was the largest prefix in the metric system before the new additions. Now, the Earth's mass can be said to be about 6 ronnagrams rather than 6,000 yottagrams.

This is the first time that new prefixes have been added to the metric system since the addition of zetta (10˄21), zepto (10˄minus21), yotta (10˄24) and yocto (10˄minus24), which were all ...