The discussion centers on mental techniques for factoring numbers without a calculator. Participants highlight the traditional method of identifying two non-prime factors and recursively factoring them. Additionally, they recommend researching "divisibility rules" or "divisibility tests" to enhance mental calculations. However, it is noted that mental factoring is primarily effective for small numbers and lacks utility in complex number theory applications.
PREREQUISITESMathematicians, students, educators, and anyone interested in improving their mental arithmetic and number theory skills.
Google "divisibility rules" or "divisibility tests" . However, mental calculations are generally restricted to working with small numbers and are not generally useful in serious number theory problems, and I don't see any advantage to excluding the use of a calculator.qntty said:Does anybody have any good tricks to quickly factor a number in your head, or a trick that can be done quickly on paper? The best method that I know without using a calculator is the traditional method of finding two not-necessarily-prime factors and factoring those with the same method.