Flashcards will really help students understand their math facts. Math facts will lead them into other math skills and help them feel comfortable with math in general. In some cultures 6 is the number for good luck. Six is a perfect number, in fact the first perfect number. If add all of its divisors (1,2,3) you will get the number itself.
Interesting Fact: The Braille language system (used by sight impaired people) is built on the use of 6 dots. 2 columns of 3 dots have been used to communicate a whole bunch.