What is the answer to 89-39
\(89 - 39 = (80 +9) - (30+9) = 80 - 30 + 9 - 9 = 80 - 30 = \boxed{50}\)
89 - 39 = 50The 9s in the ones digit 9 - 9 = 08 - 3 = 5So 50