1、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,先数出十根小棒,捆成一捆。,10个一,1个十,1个十和2个一合起来是12。,1 2,写作:,读作:十二,1个十和5个一合起来是15。,1 5,写作:,读作:十五,返回,10个一,1个十,是,11,12,12,13,14,12,15,16 ?,16,17 ?,18,2个十,20,是,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
2、,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,
3、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20,17,15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,再见,