Materials: none

Ask each member of the class when their birthday is.

Then have each student recite the Article of Faith whose number corresponds to the numbered month in which their birthday occurs. (1st Article of Faith for January, 2nd for February...).
If there is a duplicate, the second student could recite the 13th Article of Faith. If they like this activity, you could keep it going a little longer by having them reatively use the numbers of the date of their birthday to recite another Article of Faith. (If it's a double digit number, they could subtract one numeral from another or add them together to get a single number.)
Let them be creative to get an Article of Faith they know: "They are both divisible by two, so I'll say the 2nd Article of Faith."

Variation: Play the game and substitute the name of one of the Latter-Day prophets by creatively using the numbers of their birth date to come up with a number 1 through 15.