Calculate 243 base six minus 243 base five, expressing your answer in base ten

Answer 1

243₆ = 2 ∙ 6² + 4 ∙ 6¹ + 3 ∙ 6⁰ = 2 ∙ 36 + 4 ∙ 6 + 3 ∙ 1 = 72 + 24 + 3 = 99₁₀

243₅ = 2 ∙ 5² + 4 ∙ 5¹ + 3 ∙ 5⁰ = 2 ∙ 25 + 4 ∙ 5 + 3 ∙ 1 = 50 + 20 + 3 = 73₁₀

243₆ - 243₅ = 99 - 73 = 26