[ItsRobinson]

PHP код:

new QuizStage[MAX_PLAYERS];
new QuizNumbers[MAX_PLAYERS][4]
public OnPlayerText(playerid,text[])
{
    switch(QuizStage[playerid])
    {
        case 0:
        {
            new number = strval(text);
            QuizNumbers[playerid][0] = number;
            SendClientMessage(playerid, -1, "Now enter another number");
            QuizStage[playerid]++;
        }
        case 1:
        {
            new number = strval(text);
            QuizNumbers[playerid][1] = number;
            SendClientMessage(playerid, -1, "Now enter another number");
            QuizStage[playerid]++;
        }
        case 2:
        {
            new number = strval(text);
            QuizNumbers[playerid][2] = number;
            SendClientMessage(playerid, -1, "Now enter another number");
            QuizStage[playerid]++;
        }
        case 3:
        {
            new number = strval(text);
            QuizNumbers[playerid][3] = number;
            SendClientMessage(playerid, -1, "Now tell me what it equals!");
            QuizStage[playerid]++;
        }
        case 4:
        {
            new answer = QuizNumbers[playerid][0] + QuizNumbers[playerid][1] + QuizNumbers[playerid][2] + QuizNumbers[playerid][3];
            new input = strval(text);
            if(input == answer)
            {
                SendClientMessage(playerid, -1, "Congratulations you got it right!");
            }
            else SendClientMessage(playerid, -1, "Damn, that's incorrect!");
            QuizStage[playerid] = 999;
            QuizNumbers[playerid][0] = 0;
            QuizNumbers[playerid][1] = 0;
            QuizNumbers[playerid][2] = 0;
            QuizNumbers[playerid][3] = 0;
            return 1;
        }
    }
    return 1;
} 


I think this is what you was asking for? Not too sure, it doesn't make sense to do something like this, but this is what I think you wanted.
(Not tested)