In Albert Einstein’s first published work, ‘On the Electrodynamics of Moving Bodies’, he introduced a set of equations, namely which have the form ‘time=distance/velocity’, as a part of the conclusion of Section 2. In these equations, Einstein implied that an event in a moving system viewed from within that moving system differs from the same event viewed from a reference stationary system. This perspective became the fundamental basis of the special theory of relativity (STR). However, considering Sections 1 and 2 of Einstein’s paper using practical examples and numerical values, we find that an inconsistency is caused by using ‘relative speed’ as ‘velocity’ in the universal equation ‘time=distance/ velocity’. In the conventional mathematics, only ‘mobile speed’ is admitted as ‘velocity’ in ‘time=distance/velocity’. This is a pure mathematical issue that should be solved if we continue to use the STR, under the premise that Sections 1 and 2 of ‘On the Electrodynamics of Moving Bodies’ are correct.