哪位帮我看一下这段代码，为什么输入任何数都会显示 E？

#include<stdio.h>

int main()

{

char grade;

int a, temp;

printf("plese input nub:");

scanf("%d", &a);

if (a < 0 || a>100)

printf("no");

else

{

temp = a/10;

switch(temp)

{

case10:

case9:grade = 'A'; break;

case8:grade = 'B'; break;

case7:grade = 'C'; break;

default:grade='E';

}

printf("%d--->%c\n", a, grade);

}

}