35374(7-118+14)×56 (6―4―9)×36
=32—63+12 =30—27—28 =19 =-25
(-34)×(8-43-)
=-6+1+ ==- =
25×34-(-25)×12+25×14=25×(34+12+14) ==25×112 ==3712
原则四:巧妙运用运算律
66)×〔12122-(-13)+(-115)〕 -66-63-22+55 -96
(-36)×(49+56-127)
-16-30+21
-25 (- 7573852 (18+3×72 13×(214-7)×(-5)×(-16) 4-6+9)
2785=28+54-60+56 =13×(14)×(-5)×(-16)
9=78 =28
有理数除法
18÷(-3) (-24)÷6 ÷(-6)
= -6 =-4 =19 =
(+215)÷(-37) (-139)÷(-23)
=-519 = -13(-1)÷(-4)÷47 3×(-7)]
=716 =
-3÷(13-14) ×181
=-36 =457)÷(-3) (-35)÷25 (-42)
-32 =7
9 ÷(-18) -36÷(-113)÷
-2 =-4012
÷(-67)×(-79) 0÷[(-314)
4918 =0
2467)÷(-6) 2÷(5-18)117 =-117
(- =(-
733371113÷(-3)×(-3) -8×(-14)÷(-8) (4-8)÷5(-6)
34=27 =-12 =20
333353112(92-8+4)÷(-4) - ×(6-)×7÷2 -17÷(-16)×18×
(-7)
6791131=-6+12-1 =-2×(-3)×7×2 =-7×11×8×7
27=-612 =1 =-4
=-634
655555512×(-13-2)÷4 7÷(-25)-7×12-3÷4
45555551=-65×6×5 =7×(-12)-7×12-3×4
555=-4 =-12×(7+7+1 )
5 =-12×177
1 =-184
原则五:结果的形式要与题目中数的形式保持一致。如确定是分数还是小数,分数必须是带分数或真分数,不得是假分数,过程中无所谓。
×112+×(-27)-÷37+×119
=×(112+119)-241175×27-5×3
=448-7720775-3515=-35-15
=-202=-4235-5157-515
=-574105
有理数混合运算
(-16?203?45?127)×(-15×4)=10+9-48+35 ==6
2÷(-37)×47÷(-517) 118)
=1427 =×587]×9
= 15×(-5)÷(-15)×5 ??187??37?(-)
25 [1512-(114÷125+312)
]÷(-[15152-514×7-32]×89 =[12-54311862228×9=63
=95563
-(13-211+143-27)
÷(-421) 31=25 =(13-21+14-7)×42
2 =14-2+9-12=9
521-13×23-×7+3×(-13)-7× 8-(-25)÷(-5)
512=[-13×2]-×7-7× =3 3+3×(-13)
=-13-=-
(-13)×(-134)×131×(--318
=-2 =(-16-50+325)÷(-2)=8+25-1710 ==31310 =4178-+43212+531921- =178--+43212+531921 =24+4=178-100+97 =25=175
-27-(-12)+|-112| 671) (-478)-(-512)+(-414)
-8+114=-634
(-)-(-314)+-512
(-)-512+-(-)
(-6)×(-4)+(-32)÷(-8)-3
-3
(-9)×(-4)+ (-60)÷12