Sounds like you could use an array to store all those numbers, then have an
that you'd use to hold the cumulative sum of the temperatures as you looped through the array.
Something like this:
int temp[5]; //I forget how to assign values at initialization, if you even do that...
int sum = 0;
int ave = 0; //Calculated average, the output.
for(i = 0; i<5; i++)
{
sum = sum + temp[i]; //The new value is the old value plus the number stored in this section of the array.
}
ave = sum/5; //calculates average of five temperatures.
Shame on me for not having used arrays in long enough to actually forget the details on 'em, but it's the concept that's important here.
If you have a bunch of related numbers or characters or strings, using an array is a good way to organize them so you can access them iteratively. The for loop (or while loop, if you prefer) allows you to move through the array and use all the values if necessary, as long as you are careful to not exceed the size of the array.
There are ways to make the loop not require a hardcoded array length, as well. It'd be worthwhile for you to learn 'em so you know what you CAN do even if you don't know the exact details... I'm sure that others will disagree with me on that point.