JavaScript is displaying an incorrect mathematical answer

I wrote this small script that would calculate a students GPA. I decided to test it midway and it appears as if the code messes up. For example if I add 2 and 2 and 12 instead of displaying 2 it displays 1.75 which is weird. Answer You forget to add the third values so you get wrong results. If you inputs 2,2,12 result is 0.5, because of (2+2)/8 = 4/8 = 0.5. For 2,12,2 or 12,2,2 result is 1,75 because of (2+12)/8 = 14/8 = 1,75 This should give you the desired result.