Score is often kept by using 2 cards not used in normal gameplay. Of all the different ways to keep score, the Northeast system (which uses a two and a three to keep score) is infamous for being the most difficult to understand. Personally, I don't think it's all that complicated. Have a look at this.

Note that 1 through 4 are fairly self-explanatory: the number of "dots" (a generic term meaning any of the 4 suit symbols [heart, spade, diamond or club]) you see is the number your score is equal to. A score of 5 introduces a different element to the scoring as one card is lying vertically and the other horizontally. A vertical card, as previously used, represents zero plus the number of dots shown. A horizontal card crossing a vertical card (either on top of or underneath), however, represents 5 points. As you can see on a score of 5, no dots are showing but one card is horizontal across the other vertical card. In other words, 0 dots + 5 point for the crossing horizontal card = 5 total points. Now look at a score of seven: 2 dots + 5 points for the horizontal crossing card = 7 points. See, It's not so tough. No scoring representation is shown for 10 points due to the fact that, in Northeast Euchre, the game is over when a score of 10 has been achieved. If this is still too much to handle, that's okay. In the Midwest U.S., a six and four are used to keep score. Some believe that using this system, though more simplistic, is infinitely less cool. That comment is usually made by Northeasterners. Regardless, in this system, there is no "crossover" card to contend with, and the number of dots equals your score, period. For example a score of 8 can be represented by both cards face up and the four halfway covered by the six: 2 + 6 = 8 (and you thought first grade math was useless).

With this type of philosophy, you can use any low cards for keeping score. Using 2 fives to keep score isn't unheard of, though you would have to be playing in a partnership, unless you want to bust open another deck of cards just for the fives. Of course, for those who believe that cards are for playing and not scorekeeping, there is always the regular old pad and pen or pencil method of scorekeeping. This is, by far, the simplest method, accepting you can find a pencil that doesn't have the tip broken off or a pen that actually works. If you know of any other ways to keep score (like we don't have enough already!) E-mail me and I will post them.