Is 0/4 undefined? Algebra Properties of Real Numbers Division of Rational Numbers 1 Answer George C. Jun 13, 2015 #0/4 = 0# is defined. #4/0# is not. Explanation: If #4/0 = k# for some #k in RR#, then we would have #0*k = 4#, but #0*#anything# = 0 != 4#, so there is no such #k#. Answer link Related questions How do you divide rational numbers? How do you divide rational numbers in fraction form? What is the rule in dividing positive and negative rational numbers? How do you divide rational mixed numbers? How do you divide rational numbers in decimal form? How do you divide rational numbers with variables? Is division of rational numbers associative? Is division of rational numbers closed? Is division of rational numbers commutative? What is a reciprocal of a number? See all questions in Division of Rational Numbers Impact of this question 16805 views around the world You can reuse this answer Creative Commons License