Pascal之计算小系统

 program Project16;

 {$APPTYPE CONSOLE}
 VAR
 n,i,k,score,b,a:integer;
 answer,c:real;
 ch:char;
 Begin
   repeat
   writeln('1.加法练习');
   writeln('2.减法练习');
   writeln('3.乘法练习');
   writeln('4.除法练习');
   writeln('5.退出系统');
    score:=;              {得分初值为零}
    k:=;                  {答对题数初值为零}
    write('请选择练习项目：');
     readln(n);
     writeln;
      if n<> then
         begin
            if n= then writeln('结果保留两位小数');   {除法运算时提示用户要保留两位小数}
            writeln;
            for i:= to  do
             begin
               write('第',i,'题：');
               randomize;
               a:=random()+;{产生1~10内的随机数}
               b:=random()+;
               case n of
                    : begin
                         write(a,'+',b,'=');
                         read(answer);
                         if answer=a+b then     {判断输入的答案与正确答案是否相等}
                                         begin
                                           score:=score+;   {正确则加10分}
                                            k:=k+;           {记录答对的题数}
                                            writeln(' ':,'正确');
                                          end
                                        else writeln(' ':,'错误');
                         end;

                    : begin
                         write(a,'-',b,'=');
                         read(answer);
                         if answer=a-b then
                                         begin
                                            score:=score+;
                                            k:=k+;
                                            writeln(' ':,'正确');
                                          end
                                        else writeln(' ':,'错误');
                         end;
                    : begin
                         write(a,'×',b,'=');
                         read(answer);
                         if answer=a*b then
                                         begin
                                            score:=score+;
                                            k:=k+;
                                            writeln(' ':,'正确');
                                          end
                                        else writeln(' ':,'错误');
                         end;
                    : begin
                         write(a,'÷',b,'=');
                         read(answer);
                         c:=(round((a/b)*))/;
                         if answer=c then  {正确答案保留两位小数}
                                         begin
                                            score:=score+;
                                            k:=k+;
                                            writeln(' ':,'正确');
                                          end
                                        else writeln(' ':,'错误');
                         end;

                 end;
               end;
   writeln;
    write('你一个回答对了',k,'道题，','得了',score,'分。');   {输出测试结果}
   if score>= then writeln('Very Good!')
      else if score>= then writeln('Good!')
           else if score>= then writeln('Well')
               else if score>= then writeln('Pass！')
                  else writeln('Fail！');
    writeln;
    write('你想继续选择练习项目吗?',' ':,'(Y/N)',' ':);  {判断用户是否想继续测试}
    readln;
    read(ch);
    writeln
    end;
    until (ch='N')OR(CH='n')or(n=);{输入N或n则表示用户退出测试}
    end.