[ValdisSeroff]

It looks good, you're almost there.

As for your question, to make the scanf() function accept letters instead of numbers, change the format parameter (1st parameter) to "%c", which means single character (%d means decimal integer). Then use an "if" statement to test if the character is a "y" or "n"

So, the code (with changes in bold) should look something like this:

Code: [code]void main() { int a,b,c,d,h,z; while(a!=2){ char y; printf("Please make a choice\n"); printf("1-Grade Calculation\n"); printf("2-END\n"); scanf("%d", &a); if (a==1){ printf("Please enter your first grade:"); scanf("%d", &b); printf("\n"); printf("Please enter your second grade:"); scanf("%d", &c); printf("\n"); printf("Please enter your third grade:"); scanf("%d", &d); printf("The average is:"); h=(b+c+d)/3; printf("%d", h); printf("\n"); <b>if(h>=90 && h=80 && h=70 && h=60 && h=0 && h