(a是大于0的自然数),当a 时,是真分数,当a 时,是假分数,当a 时,等于3.
9: =0.75==21÷ = :4.
5÷8= : = = %.
:4=0.75== %
= ÷ 29÷18= 0.15= .
3:4=12: = :12= %