小學(xué)數(shù)學(xué)人教2011課標(biāo)版一年級十幾減9的減法 (7).ppt

1、,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=,11,14,11,11,14,11,13,12,11,14,15,12,11-（ ）=10,1,12-（ ）=10,2,13-（ ）=10,3,14-（ ）=10,4,15-（ ）=10,5,16-（ ）=10,6,9,8,4,6,5,5,擺一擺，算一算。,10-9=1；1+( )=( )。,9+( )=12； 12-9=( )。,3,你喜歡哪種方法？ 還可以怎樣計算？,3,3,2,3,6,做減法，想加法。,139,8,3,7,5,2,4,6,159,149,189

2、,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

3、,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,我們一隊有12個男生,老師讓兩個男生之間 插進一個女生,1,2,3,4,5,6,7,8,9,10,11,12,答：一共可以插進11個女生。,書本P26,11 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 = 2 12 9 = 3 13

4、9 = 4 14 9 = 5 15 9 = 6 16 9 = 7 17 9 = 8 18 9 = 9,十幾減9， 是幾加1,=,給、或=找個家 。 12-9 4 11-9 11+9 13-3 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

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,我們一隊有12個男生,老師讓兩個男生之間 插進一個女生,1,2,3,4,5,6,7,8,9,10,11,12,答