Combining the pieces, you have the following program:
#include/* Define the trade structure */ struct trade {double price; int number;}; /* Define value-computing function */ double trade_price (struct trade *tptr) { return tptr -> price * tptr -> number; } /* Define trade array */ struct trade *trade_pointers[100]; main ( ) { /* Declare various variables */ int limit, counter, number; double price, sum = 0.0; /* Read numbers and stuff them into array */ for (limit = 0; 2 == scanf ("%lf%i", &price, &number); ++limit) { trade_pointers[limit] = (struct trade*) malloc (sizeof (struct trade)); trade_pointers[limit] -> price = price; trade_pointers[limit] -> number = number; } /* Display value of shares traded */ for (counter = 0; counter < limit; ++counter) sum = sum + trade_price(trade_pointers[counter]); printf ("The total value of the %i trades is %f.\n", limit, sum); } --- Data --- 10.2 600 12.0 100 13.2 200 --- Result --- The total value of the 3 trades is 9960.000000.