If Einstein Can Do It...
In 1915, Albert Einstein divided by zero! And, almost got away with it...
The situation: Einstein introduced the “Cosmological Constant” into the field equations of his General Theory of Relativity. In his view, the universe was stable and unchangeable in time; thus, he needed the constant to eliminate the equation's implication that "the universe was not in a steady state."
In 1922, the Russian mathematician Alexander Friedmann showed that Einstein’s had essentially divided by zero. Thus, Einstein's relativity equations suggested an expanding universe.
Like all math students, Friedmann’s claim "irked" Einstein for some time. Finally, in 1923 Einstein admitted that he had made an error.
By 1930, Einstein had thrown away his idea of the Cosmological Constant, as well as the idea that the cosmos was stable and unchangeable over time.
Many years later, Einstein had a discussion with physicist George Gamow (one of Friedmann’s students)..where Einstein remarked that "the introduction of the Cosmological Constant was the greatest scientific blunder of his life."
So, math errors happen to the best of us!
Source: Scientific American, August 1956, p. 140