20 以上的数词,20+80=100,30+70=100,40+60=100,10+90=100,50+50=100,20 是 twenty30 是 thirty40 是 forty50 是 fifty60 是 sixty70 是 seventy80 是 eighty90 是 ninety100 是 hundred,Lets learn,重点句型,加上等于,加法: plus is .,重点句型,减去等于,减法: minus is .,Fifty plus ten is sixty.,+,One hundred minus ten is ninety.,_,Forty plus twenty is sixty.,+,Seventy plus ten is eighty.,+,Sixty plus ten is seventy.,+,_,Seventy minus ten is sixty.,+,Seventy plus twenty is ninety.,ninety minus twenty is seventy.,_,Thank you !,