How about: 2*3*5 = 30 which is the product of the 1st three prime numbers
Since there are infinitely many primes, there are infinitely many numbers that are products of 3 primes.
Food doesn't exactly have model numbers but the food has a number to identify what product it is.
30, 42, 66, 70, 78
If the signs of both numbers are the same, the product will be positive. If the signs of the numbers are different, the product will be negative.
The product of negative number and a positive number is always a negative. The product of two positive numbers, or two negative numbers, is always a positive.