CMD:calculate(playerid, params[])
{
    new Float:Value1, Method[20], Float:Value2, string[128];
    if(sscanf(params, "ffs", Value1, Value2, Method))
    {
        SendClientMessage(playerid, GREY, "SYNTAX: /calc(ulate) [value] [value] [method]");
        SendClientMessage(playerid, GREY, "Method: Add, Subtract, Multiply & Divide.");
    }
    else
    {
        if(strcmp(Method, "add", true) == 0)
        {
            new Float:Sum = Value1 + Value2;
            format(string, sizeof(string), "%f + %f = %f.", Value1, Value2, Sum);
            SendClientMessage(playerid, WHITE, string);
        }
    }
    return 1;
}

format(string, sizeof(string), "%0.2f + %0.2f = %0.2f.", Value1, Value2, Sum);