【Question 2】 7 consecutive natural numbers, each of which is a composite number, the minimum sum of these 7 consecutive natural numbers is
Prime numbers within 100: $2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73,$ 79, 83, 89, 97. It is observed that there are exactly 7 consecutive composite numbers between 89 and 97: 90, 91, 92, 93, 94, 95, 96. Therefore, the smallest sum of these 7 consecutive natural numbers is $90+91+92+93+94+95+96=93 \times 7=651$.