1、 (480-120)÷(120÷4) =12 1512÷(5x78-384) =252(36+66÷2)x17 =1173 2、 480-400=80; 120-98=22; 80x22=1760; (450-400)x(120-98)=1760 24-18=6; 350÷7=50;6x50=300; (24-18)x(350÷7)=300 3、 75x6+75x4=750 ; 420+30÷15-5=417 ; (32+18)x(60-40)=50x20=1000 75x(6+4)=750 ; (420+30)÷(15-5)=45 ; 32+18x(60-40)=392 4、 (150+150+20)x2=640棵 5. (18+20)x6=234个 |