用竖式计算26×21时,先算 ,再算 ,然后把两次乘得的积 和 加起来,26×21= .
=== ÷ .
= ÷5=0.8=4: = %= 折.
÷8=0.25= %= :16.
==8÷ == (小数).
÷4==15÷ = = 折.