The mathematical constant e is approximately equal to 2.718281828, with its decimal representation extending infinitely without repeating. While some participants in the discussion recall specific digits of e, the exact value is best expressed symbolically as "e." There is no standard number of decimal places that mathematicians typically round to, but for practical purposes, three decimal places are often sufficient in educational settings. The conversation highlights the challenge of memorizing the digits of e, with one user sharing a mnemonic technique for recalling certain digits. Overall, the discussion emphasizes the infinite nature of e's decimal expansion and the preference for using its symbolic form in precise calculations.