C言語を使用して数値範囲を出力するにはどうすればよいですか?

lower= (n/10) * 10; /*the arithmetic operators work from left to right*/
upper = lower+10;

#include<stdio.h>
main(){
   int n,lower,upper;
   printf("Enter a number:");
   scanf("%d",&n);
   lower= (n/10) * 10; /*the arithmetic operators work from left to right*/
   upper = lower+10;
   printf("Range is %d - %d",lower,upper);
   getch();
}

Enter a number:25
Range is 20 – 30

#include<stdio.h>
main(){
   int number,start,end;
   printf("Enter a number:");
   scanf("%d",&number);
   start= (number/10) * 10; /*the arithmetic operators work from left to right*/
   end = start+10;
   printf("Range is %d - %d",start,end);
   getch();
}

Enter a number:457
Range is 450 – 460