#include <stdio.h>
#include <stdlib.h>

int main ()
{
  int i,n,big;
  int * pData;
  printf ("Amount of numbers to be entered: ");
  scanf ("%d",&i);
  pData = (int*) calloc (i,sizeof(int));
  if (pData==NULL) exit (1);

  for (n=0;n<i;n++)
  {
      printf ("Enter number #%d: ",n);

    scanf ("%d",&pData[n]);
  }
 big=pdata[0];
 for(n=0;n<i;n++)
 {
     if(big>pdata[n])
     {
         big=pdata[n];
     }
     printf("%d",big);

}
}

what is the error??

if(big>pdata[n])

Are you saying here:
if "big" is greater than the number in the array, then replace it?


[After that]
Are you going to free the data allocated on line 10?

#include <stdio.h>
#include <stdlib.h>

int main ()
{
  int i,n,big;
  int * pData;
  printf ("Amount of numbers to be entered: ");
  scanf ("%d",&i);
  pData = (int*) calloc (i,sizeof(int));
  if (pData==NULL) exit (1);

  for (n=0;n<i;n++)
  {
      printf ("Enter number #%d: ",n);

    scanf ("%d",&pData[n]);
  }
 big=pdata[0];
 for(n=0;n<i;n++)
 {
     if(pdata[n]>big)
     {
         big=pdata[n];
     }
     printf("%d",big);

}
free(pdata);
return 0;
}

but this is also showing error

but this is also showing error

The code has syntax errors. C is case sensitive, but you use both pData and pdata to mean the same thing. Try this instead:

#include <stdio.h>
#include <stdlib.h>

int main ()
{
    int i,n,big;
    int * pdata;
    printf ("Amount of numbers to be entered: ");
    scanf ("%d",&i);
    pdata = (int*) calloc (i,sizeof(int));
    if (pdata==NULL) exit (1);

    for (n=0; n<i; n++)
    {
        printf ("Enter number #%d: ",n);
        scanf ("%d",&pdata[n]);
    }
    big=pdata[0];
    for(n=0; n<i; n++)
    {
        if(pdata[n]>big)
        {
            big=pdata[n];
        }
        printf("%d",big);

    }
    free(pdata);
    return 0;
}

But your algorithm is excessively complicated. There's no need to store the numbers since you only need to retain the biggest one found so far:

#include <stdio.h>

int main(void)
{
    int num;
    
    printf("Enter a series of numbers (EOF to stop): ");
    
    // Get the first number separately to simplify the logic
    if (scanf("%d", &num) == 1)
    {
        int largest = num;
        
        // Now get the rest of the numbers and find the largest
        while (scanf("%d", &num) == 1)
        {
            if (num > largest)
            {
                largest = num;
            }
        }
        
        printf("The largest was %d\n", largest);
    }
    else
    {
        printf("No numbers were entered.\n");
    }
    
    return 0;
}

OK. You could have just changed the > to a <, but that's OK.

Where does it show or give an error?

it shows 3 erros like this 1.pdata undeclared(first use in this function)
2.each undeclared identifier is reported only onc
3.for each function it appears

it shows error in 18th line

Did you see what deceptikon said?

is c case sensitive???i thought java was only case sensitive

is c case sensitive???i thought java was only case sensitive

Nope, Java didn't corner the market on case sensitivity. A lot of languages that aren't Java are case sensitive, most of them, in fact. :D