當(dāng)自然數(shù)n的個(gè)位數(shù)分別為0,1,2,…,9時(shí),n2,n3,n4,n5的個(gè)位數(shù)如表所示:
n的個(gè)位數(shù) |
0 |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
n2的個(gè)位數(shù) |
0 |
1 |
4 |
9 |
6 |
5 |
6 |
9 |
4 |
1 |
n3的個(gè)位數(shù) |
0 |
1 |
8 |
7 |
4 |
5 |
6 |
3 |
2 |
9 |
n4的個(gè)位數(shù) |
0 |
1 |
6 |
1 |
6 |
5 |
6 |
1 |
6 |
1 |
n5的個(gè)位數(shù) |
0 |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
(1)從所列的表中你能發(fā)現(xiàn)什么規(guī)律?
(2)若n為自然數(shù),和數(shù)1981
n+1982
n+1983
n+1984
n不能被10整除,那么n必須滿足什么條件?