20以內(nèi)的退位減法,復(fù)習(xí)：,9+2= 8+6= 7+4=6+5= 5+9= 4+7=8+5= 7+5= 8+3=9+5= 7+8= 5+7=,11,14,11,11,14,11,13,12,11,14,15,12,9+6=,9+7=,9+3=,15,16,12,9+8=,17,9+4=,13,9+5=,14,9+2=,11,9+（ ）=12,3,5,擺一擺，算一算。,10-9=1；1+( )=( )。,9+( )=12；12-9=( )。,3,你喜歡哪種方法？還可以怎樣計(jì)算？,3,3,2,3,做一做,128=4（個）,114=7（只）,計(jì)算,12-5= 11+0= 12-3= 14+4= 10-6= 11-5= 10-4= 13-7= 6+9= 13-9= 11-9= 12-0=,7,11,9,18,4,6,6,6,15,4,2,12,跳木樁,=,給、或=找個家 。 12-9 4 11-9 11+913-3 13-9 18- 9 9,139,8,3,7,5,2,4,6,159,149,189,179,129,119,169,139,8,3,7,5,2,4,6,159,149,189,179,129,119,169,139,8,3,7,5,2,4,6,159,149,189,179,129,119,169,8,3,7,5,2,4,6,159,149,189,179,129,119,169,139,8,3,7,5,2,4,6,159,149,189,179,129,119,169,139,8,3,7,5,2,4,6,159,149,189,179,129,119,169,139,8,3,7,5,2,4,6,159,149,189,179,129,119,169,139,8,3,7,5,2,4,6,159,149,189,179,129,119,169,139,8,3,7,5,2,4,6,159,149,189,179,129,119,169,139,8,3,7,5,2,4,6,159,149,179,129,119,169,139,189,13-9,14-9,15-9,勝利,19-9,17-9,12-9,11-9,18-9,20-9,（ ）-9=5,16-9,入口,樹上原來有14只小鳥，,飛走了9只小鳥。,原來有1個松果，小松鼠搬走了9 個。,14-9=5（只）,15-9=6（個）,11 9 = 2,12 9 = 3,13 9 = 4,14 9 = 5,15 9 = 6,16 9 = 7,17 9 = 8,18 9 = 9,11 9 = 212 9 = 313 9 = 414 9 = 515 9 = 616 9 = 717 9 = 818 9 = 9,