简便计算4/15-3/8+11/15-5/8=(4/15+11/15)-(3/8+5/8)=1-1=0
计算如下:3/8×4/15+11/15×5/8 =3/2×1/15+11/3×1/8 =1/2×1/5+11/3×1/8 =1/10+11/24 =12/120+55/120 =67/120 乘法的计算法则:1、多位数乘法法则整数乘法低位起,几位数乘法几次积。个位...