Q:

Type of formal parameter 1 is incomplete

I'm trying to write a program that adds two rational numbers with structures 
and this is the code
#include <stdio.h>
#include <stdlib.h>

struct Fraction{
                int numerator ;
                int denominator ;
                };

int mainMenu(void);
struct Fraction readStructure(void); /*this works well*/
struct Fraction add(struct Fractoin num1, struct Fraction num2);/*this doesn't*/

int main()
{
    struct Fraction num1 = readStructure();
    struct Fraction num2 = readStructure();

    struct Fraction result = add(num1, num2) ;

    return 0 ;
}
struct Fraction readStructure(void)
{
    struct Fraction temp;

    printf("-> Enter the numerator : ");
    scanf("%d", &temp.numerator);
    printf("-> Enter the denominator : ");
    scanf("%d", &temp.denominator);
    while(temp.denominator == 0)
    {
        printf("--> Zero in the denominator isn't possible.. try again : ");
        scanf("%d", &temp.denominator);
    }

    return temp ;
}
struct Fraction add(struct Fractoin num1, struct Fraction num2)
{
    struct Fraction temp;

    temp.numerator = (num1.numerator * num2.denominator) +
                     (num2.numerator * num1.denominator);
    temp.denominator = num1.denominator * num2.denominator ;

    return temp ;
}

the compiler says it's wrong and gives me those errors + some more warnings..
error: type of formal parameter 1 is incomplete.
error: parameter 1 ('num1') has incomplete type.

A:

struct Fraction add(struct Fraction num1, struct Fraction num2);

Fraction spelling mistake :)

