8^(7^(6^(5^(4^(3^(2^1))))))

[(a)^b implies 'a' raised to the power of 'b', ((a)^b)^c implies 'a' raised to the power 'bc', but a^(b^c) implies 'a' raised to the power 'b' raised to the power 'c'.]

The last digit would be 6 if the association were ((((((8^7)^6)^5)^4)^3)^2)^1, as that would be 8^(7!), where the exponent is a multiple of 4. However, the association (order of taking the powers) is right-to-left, not left-to-right.
Edited on December 31, 2003, 11:00 am

Posted by Charlie on 2003-12-31 10:58:39