2020 以内的退位减法以内的退位减法 14 - 9 = 5 圈一圈,算一算。10-9=1 ; 1+( )=( ) 。9+( )=12 ;12-9=( ) 。12 - 9 = 3还可以怎样计算?3323 树上原来有 14 只小鸟,飞走了 9 只小鸟。树上还有几只小鸟?原来有 1 5个松果,小松鼠搬走了 9 个。还有几个松果?14-9=5 (只)15-9=6 (个) 11 - 9 = 212 - 9 = 313 - 9 = 414 - 9 = 515 - 9 = 616 - 9 = 717 - 9 = 818 - 9 = 9 11 - 9 = 212 - 9 = 313 - 9 = 414 - 9 = 515 - 9 = 616 - 9 = 717 - 9 = 818 - 9 = 9 13 -9837524615 - 914 -918 -917 -912 -911 -916 -9 13 -9837524615 - 914 -918 -917 -912 -911 -916 -9 13 -9837524615 - 914 -918 -917 -912 -911 -916 -9 837524615 - 914 -918 -917 -912 -911 -916 -913 -9 837524615 - 914 -918 -917 -912 -911 -916 -913 -9 837524615 - 914 -918 -917 -912 -911 -916 -913 -9 837524615 - 914 -918 -917 -912 -911 -916 -913 -9 837524615 - 914 -918 -917 -912 -911 -916 -913 -9 837524615 - 914 -918 -917 -912 -911 -916 -913 -99 837524615 - 914 -917 -912 -911 -916 -913 -9918 -9