To "sum numbers from one to nine" means to add them, and that's all it can mean. 1+2+3+4+5+6+7+8+9 = 45 45 is the only answer you can get if you "sum numbers from one to nine". You can't possibly get 20. So if you meant something else beside what you wrote, then change the wording from "sum numbers from one to nine" and explain what you meant. Edwin