11-20各数的认识-PPT.ppt

九年义务教育人教版小学数学第一册第七单元,1120各数的认识,生活中经常会遇到比10大的数，今天我们就来认识这样的数1020各数的认识。,一、借助生活，引出新知,二、探索新知,图上哪些物体的数量比10多？,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,二、探索新知,我们来数数小棒吧！,先数出十根小棒，捆成一捆。接着怎么数?,二、探索新知,二、探索新知,一个十,（）个一,十一,十二,十三,十四,十五,十六,十七,十八,十九,10,二十,二、探索新知,一个十,一个十,（20）,1 2,写作：,读作：十二,1个十和2个一合起来是12。,二、探索新知,二、探索新知,1 5,写作：,读作：十五,1个十和5个一合起来是15。,二、探索新知,1 个十和 1 个一合起来是十一。,11十一,15十五,20二十,二、探索新知,说说数的组成：,11,13,15,二、探索新知,19,（2个十就是20）,20,1个十，1个一，合起来是11；1个十，2个一，合起来是12；1个十，3个一，合起来是13；1个十，4个一，合起来是14；1个十，5个一，合起来是15；1个十，6个一，合起来是16；1个十，7个一，合起来是17；1个十，8个一，合起来是18；1个十，9个一，合起来是19；2个十，0个一，合起来是20。,拍手歌,二、探索新知,0,0,0,1,0,1,2,0,1,2,3,0,1,2,3,4,0,1,2,3,4,5,0,1,2,3,4,5,6,0,1,2,3,4,5,6,7,0,1,2,3,4,5,6,7,8,0,1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,10,0,1,2,3,4,5,6,7,8,9,10,11,0,1,2,3,4,5,6,7,8,9,10,11,12,0,1,2,3,4,5,6,7,8,9,10,11,12,13,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,14,17,从7数到17,从11数到20,数出12后面的数,数出18前面的数,15和17,一个一个数,两个两个数,五个五个数,1个十,1个十,6个一,？,16,2个十,20,抢答题:,（1）15是由()个十和()个一组成,（2）()个十和()个一组成17,（3）16前面一个数是(),后面一个数是(),（4）与19相邻的两个数是()和(),1,1,15,18,5,7,17,20,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,（3）15是由()个十和()个一组成。,我会答:,（4）()个一和()个十和起来13。,（2）16前面一个数是(),后面一个数是()。,（6）与19相邻的两个数是()和()。,（5）16和18中间的一个数是（）。,（1）比10多1的是（），比17少1的是（）。,11,16,15,17,1,5,1,3,17,18,20,三、实践应用,(),(),十位,个位,(),14,十四,20,二十,10,十,20,二十,写一写，读一读。,三、实践应用,用数字卡片摆出下面各数。,十六十四,十一十七,十九二十,1,1,1,9,1,4,1,7,2,0,