记忆口诀：

　　基变序,有规律,词尾加上-th.

　　一,二,三,特殊记,词尾字母t,d,d.

　　八去t,九除e,ve要用f替,ty将y变成i,th前面有个e.

　　若是碰到几十几,前用基来后用序.

　　整十基数变序数,先把ty变成tie,要是遇上两位数,十位基数,个位序,th最后加上去.

　　或者

　　一,二,三变字体；th从4上起；8加h,9减e；用f代ve；ty变为tie.

　　1至100序数词：

　　第1first1st

　　第2second2nd

　　第3third3rd

　　第4fourth4th

　　第5fifth5th

　　第6sixth6th

　　第7seventh7th

　　第8eighth8th

　　第9ninth9th

　　第10tenth10th

　　第11eleventh11th

　　第12twelfth12th

　　第13thirteenth13th

　　第14fourteenth14th

　　第15fifteenth15th

　　第16sixteenth16th

　　第17seventeenth17th

　　第18eighteenth18th

　　第19nineteenth19th

　　第20twentieth20th

　　第21twenty-first21st

　　第22twenty-second22nd

　　第23twenty-third23rd

　　第24twenty-fourth24th

　　第25twenty-fifth25th

　　第26twenty-sixth26th

　　第27twenty-seventh27th

　　第28twenty-eighth28th

　　第29twenty-ninth29th

　　第30thirtieth30th

　　第31thirty-first31st

　　第32thirty-second32nd

　　第33thirty-third33rd

　　第34thirty-fourth34th

　　第35thirty-fifth35th

　　第36thirty-sixth36th

　　第37thirty-seventh37th

　　第38thirty-eighth38th

　　第39thirty-ninth39th

　　第40fortieth40th

　　第41forty-first41st

　　第42forty-second42nd

　　第43forty-third43rd

　　第44forty-fourth44th

　　第45forty-fifth45th

　　第46forty-sixth46th

　　第47forty-seventh47th

　　第48forty-eighth48th

　　第49forty-ninth49th

　　第50fiftieth50th

　　第51fifty-first51st

　　第52fifty-second52nd

　　第53fifty-third53rd

　　第54fifty-fourth54th

　　第55fifty-fifth55th

　　第56fifty-sixth56th

　　第57fifty-seventh57th

　　第58fifty-eighth58th

　　第59fifty-ninth59th

　　第60sixtieth60th

　　第61sixty-first61st

　　第62sixty-second62nd

　　第63sixty-third63rd

　　第64sixty-fourth64th

　　第65sixty-fifth65th

　　第66sixty-sixth66th

　　第67sixty-seventh67th

　　第68sixty-eighth68th

　　第69sixty-ninth69th

　　第70seventieth70th

　　第71seventy-first71st

　　第72seventy-second72nd

　　第73seventy-third73rd

　　第74seventy-fourth74th

　　第75seventy-fifth75th

　　第76seventy-sixth76th

　　第77seventy-seventh77th

　　第78seventy-eighth78th

　　第79seventy-ninth79th

　　第80eightieth80th

　　第81eighty-first81st

　　第82eighty-second82nd

　　第83eighty-third83rd

　　第84eighty-fourth84th

　　第85eighty-fifth85th

　　第86eighty-sixth86th

　　第87eighty-seventh87th

　　第88eighty-eighth88th

　　第89eighty-ninth89th

　　第90ninetieth90th

　　第91ninety-first91st

　　第92ninety-second92nd

　　第93ninety-third93rd

　　第94ninety-fourth94th

　　第95ninety-fifth95th

　　第96ninety-sixth96th

　　第97ninety-seventh97th

　　第98ninety-eighth98th