Notice the pattern generated by raising a number ending in 7 to the following powers.....
7^1 = 7 7^2 = 49 7^3 = 343 7^4 = 2401
And this cyclic pattern repeats every four powers
So ... 256/4 = 64
And this whole number tells us that 7^256 completes a cycle of 4, so this number ends in a "1"
Notice the pattern generated by raising a number ending in 7 to the following powers.....
7^1 = 7 7^2 = 49 7^3 = 343 7^4 = 2401
And this cyclic pattern repeats every four powers
So ... 256/4 = 64
And this whole number tells us that 7^256 completes a cycle of 4, so this number ends in a "1"