c - C エラー 3 エラー C2065: 'num1': 宣言されていない識別子

Question

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


int main(){
    char letter;
    printf("Choose your calculation operation:7n/tA:Addition/n/tB:Subtraction/n/tC:Multiplacation/n/tD:Division/n/t");
    scanf("%c/n",letter);
    float num1, num2;
    printf("Enter a Num:");
    scanf("%f/n",&num1);
    printf("Enter the second Num:");
    scanf("%f/n",&num2);
     if(letter=='A' || letter=='a') printf("%f + % f = %f",num1,num2,(num1+num2));
     else if(letter=='B'||letter=='b') printf("%f - % f = %f",num1,num2,(num1-num2));
     else if(letter=='C'||letter=='c') printf("%f * % f = %f",num1,num2,(num1*num2));
     else if(letter=='B'||letter=='b') printf("%f / % f = %f",num1,num2,(num1/num2));
     else printf("You choosed wrong mark.");

}