新人教版一年级数学下册十几减九精装版.ppt
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,二十以内退位减法,十几减九(复习课),9+6=,9+7=,9+3=,15,16,12,9+8=,17,9+4=,13,9+5=,14,9+2=,11,9+()=12,3,开火车,水果店,我买个。
还剩多少个?
13-9=4,算一算,有十三颗太阳,拿去九颗太阳。
还剩几颗?
13-9=,4,想:
九加()=13,4,十六只兔子减去九只还剩几只?
16-9=,7,想:
9加()=16,7,15-9=,6,想:
9加()得15。
6,17-9=,想:
9加()得17。
8,18-9=,9,想:
9加()得18。
9,8,12-9=3(只),树上原来有14只小鸟,,飞走了9只小鸟。
原来有1个松果,小松鼠搬走了9个。
14-9=5(只),15-9=6(个),跳木桩,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,胜利,19-9,17-9,12-9,11-9,18-9,20-9,()-9=5,16-9,入口,+=14,+=15,=(),=(),=(),=(),+=18,-=2,7,7,7,7,8,9,9,9,9,7,认真想一想,你真棒!
119=2,129=3,139=4,149=5,159=6,169=7,179=8,189=9,仔细观察,你发现了什么?
119=2129=3139=4149=5159=6169=7179=8189=9,仔细观察,你发现了什么?
119=2,129=3,139=4,149=5,159=6,169=7,179=8,189=9,得数只要看十几的个位是几,得数就是比几多1,199=10,13,9,=,4,17,9,=,8,12,9,=,3,15,9,=,6,18,9,=,9,14,9,=,5,巧算“十几减9”:
就是把被减数个位上的数加1就是“十几减9”的差。
11,9,=,2,再见,