text: Scales on the most common `` 10-inch '' models are actually 25 cm , as they were made to metric standards , though some rules offer slightly extended scales to simplify manipulation when a result overflowed .
simplified: Scales on the most common `` 10-inch '' models are actually 25 cm in length , as they were made to metric standards , though some rules offer slightly extended scales to simplify manipulation when a result overflowed .