A popular problem in mathematics classes about problem solving concerns finding the unit’s digit of a large power of a number. An example of this might be:

**Find the unit’s digit of 2 ^{4000}.**

Of course, the student solving this isĀ *not* expected to compute 2 used as a factor 4000 times. The reasons should be obvious. Rather the solver begins by looking for patterns, and armed with that knowledge, deduce the answer in a simple, straight-forward manner.

We propose now the following variation on this theme:

**State the 2-digit number formed
by the finalĀ pair of digits of 2^{2004}.**

Explain your process clearly, with enough data to establish your claim.

Please note: use of a simple calculator (with 8- or 10-digit displays) is permitted, however, such computing aid is not really even necessary. What is not permitted is the use of high-powered computing software, such as Mathematica.