23.5+14.8+36.5=23.5+36.5+14.8=60+14.8=74.819.4+30.6+45.62=50+45.62=95.6233.5+24.9+51.3=58.4+51.3=109.7 39.7×2.8+3.97×72 =3.97×10×2.8+3.97×72 =3.97×28+3.97×72 =3.97×（28+72） =3.97×100 =397 32...
急需300道四年级递等式计算题!要难些,不要有乘除,最好能简便
23.5+14.8+36.5=23.5+36.5+14.8=60+14.8=74.819.4+30.6+45.62=50+45.62=95.6233.5+24.9+51.3=58.4+51.3=109.7 39.7×2.8+3.97×72 =3.97×10×2.8+3.97×72 =3.97×28+3.97×72 =3.97×（28+72） =3.97×100 =397 32...