笔算加法时,个位相加满十向 进一;笔算减法时,个位不够减,就从 退一当作 再减.
= ÷ === (小数)= (百分数)= (成数)
0.16==2÷ =8: = %
0.75==6÷( )=12:( )=( )%
0.25== :16=5÷ = %
:20=0.8=12÷ == %= (填成数)