3~(100)是几位数?它的末位数字是多少?末两位数字又是多少? 对于3~(100)是几位数,通过对数运算易知,它是一个48位数。至于它的末位数字,十位数字是多少,推到更一般n~k(n,k∈N)的个位数字是多少,十位数字又是多少,那就稍微困难一些,本文就来探讨这个问题。为此,我们先来证明: 定理1 n~5-n能被10整除。(n∈N) 证明:∵n~5-n=n(n~4-1)=n(n+1)(n-1)(n~2+1) 3~(100) is a few digits? What is the last digit? What is the last two digits? For 3~(100) it is a few digits. It is easily known by the logarithmic operation. It is a 48-digit number. . As for its final figure, what is the ten-digit figure, what is the number of single digits pushed to a more general n~k(n,k∈N), and what is the number of ten digits? That would be a bit more difficult. Explore this issue. For this purpose, we first prove that: Theorem 1 n~5-n can be divisible by 10. (n∈N) Proof: ∵n~5-n=n(n~4-1)=n(n+1)(n-1)(n~2+1)