85 又1/3×3/8+71 又1/6×6/7+56 又1/4×4/5= 简便算法怎么算?

问题描述:

85 又1/3×3/8+71 又1/6×6/7+56 又1/4×4/5= 简便算法怎么算?

=(85+1/3)×3/8+(71+1/6)×6/7+(56+1/4)×4/5
=(80+5又1/3)×3/8+(70+1又1/6)×6/7+(50+6又1/4)×4/5
=(80+16/3)×3/8+(70+7/6)×6/7+(50+25/4)×4/5
=80×3/8+16/3×3/8+70×6/7+7/6×6/7+50×4/5+25/4×4/5
=30+2+60+1+40+5
=138