Right Brain Math:an EZ way to learn numbers

A prime number is a natural number greater than 1 which has exactly two distinct natural number divisors: 1 and itself.  According to Wikipedia, a formula for primes is a formula generating the prime numbers, exactly and without exception. No easily-computable such formula is known.

During an in-service for teachers at Franklin School in Santa Barbara, a teacher noticed that prime numbers show up on the EZ Times Line Table, a variation of the EZ Times Table. I had never noticed that, although it makes perfect sense since prime numbers are those without factors. The table visually shows all factors for the numbers 1-50. For prime numbers 2, 3, 5, and 7, only these numbers themselves show up as factors. Going beyond 7, looking for numbers that have only dots (no factors) reveals that 11, 13, 17, 23, 29, 31, 37, 41, 43, and 47 are prime numbers!  If we continue the Table, we will find more prime numbers in this VISUAL PATTERN solution to finding prime numbers (53, 59, 61, 67, 71, etc.).

The simple, visual patterns, including factors and prime numbers, of the EZ Times Table are powerful and obvious even to grade school students.