第一种 (300+6)×12 =300×12+6×12 =3600+72 =3672 25×(4+8) =25×4+25×8 =100+200 =300 32×(25+125) =32×25+32×125 =4×25×8+8×125×4 =4800 第二种 84×101 =84×(100+1) =84×100+84×1 =8400+84 =8484 504×25 =(500+4)×25 =500×25+25×4 =12500+100 =12600 704×25 =(700+4)×25 =700×25+25×4 =17500+100 =17600 第三种 99×64 =(100-1)×64 =100×64-64×1 =6400-64 =6336 99×16 =(100-1)×16 =16×100-16×1 =1600-16 =1584 99×27 =(100-1)×27 =100×27-27×1 =2700-27 =2673