Compare NSArray elements to NSNumber

I'm new to objective c. I am getting my data from an NSArray and want to return value according to some condition. My code is:

  NSArray *myData;
  NSNumber *day = 5;

  myData = [NSArray arrayWithObjects: @"5", nil];

  for (int i = 0; i < [myData count]; i++) {
      if(day == myData[0]){
      NSLog(@"date in valueForDay %@ ", da );
       return 3;
   }
 }

Above code doesn't execute my statements (NSLog and return one). But if i statically compare day with any number it got executed. Like:

  NSArray *myData;
  NSNumber *day = 5;

  myData = [NSArray arrayWithObjects: @"5", nil];

  for (int i = 0; i < [myData count]; i++) {
      if(day == 5){
      NSLog(@"date in valueForDay %@ ", da );
       return 3;
   }
 }

can anyone please tell me where i'm doing wrong?