班級：姓名:________成績：_____

一、求加數(shù)或求因數(shù)的方程

加數(shù)=和一加數(shù)

7+x=19x+120=17658+x=90

x+150=29079.4+x=95.5x+55=129

x+3=18x+32=76100+x=310

因數(shù)=積+因數(shù)

7x=639x=4.54.4x=444

4.5x=905x=1006.2x=1241.8x=0.972

7x=4920x=408x=81.2x=81.6

二、求被減數(shù)或求被除數(shù)的方程

被減數(shù)=差+減數(shù)

X—6=19X—3.3=8.9X—25.8=95.4

x-54.3=100x-77=275x—58=144

x—6=12x—7.6=8x—5.3=3.49

被除數(shù)=商乂除數(shù)

x+1.25=8x+4.4=10x4-78=10.5

x+2.5=100x4-3=33.3x+2.2=8x4-6=12

三、求減數(shù)或除數(shù)的方程

減數(shù)=被減數(shù)一減數(shù)

9-x=4.573.2—x=52.587—x=22

66—x=32.377-x=21.999—x=61.9

88-x=8043-x=3854-x=24

除數(shù)=被除數(shù)子商

3.34-x=0.38.84-x=4.494-x=0.03

74-x=0.001564-x=5394-x=3

914-x=1.30.2454-x=0.35104-x=8

四、帶括號的方程(先將小括號內(nèi)的式子看作一個整體來計算，然

后再來求方程的解)

3X(x-4)=46(8+x)4-5=15

先把(x—4)當作因數(shù)算。先把(8+x)當作被除

數(shù)算。

(x+5)4-3=16154-(x+0.5)=1.5

先把(x+5)當作算。先把(x+0.5)當作

舁°

五、含有兩個未知數(shù)的,我們可以用乘法分配律來解答，求出方程

的解。

12x+8x=4012x—8x=4012x+x=26

x+0.5x=6x—0.2x=321.3x+x=26

3x+5x=4814x-8x=1224-3x=3

(0.5+x)+x=9.84-27(x-2)=2x+3(x-140)4-70=4

人教版五年級上冊數(shù)學期末豎式、方程、簡算、列式計算練習

一、豎式計算

30.9X2.75.954-27.6(得數(shù)保留兩位小數(shù))7.454-3.8

（商保留2位小數(shù)）

1.44X0.255.61+6.1(保留兩位小數(shù))14.2

+11（商用循環(huán)小數(shù)表示）

3.9X0.4551.54-

864004-75

（得數(shù)保留兩位小數(shù)）（得數(shù)保

留兩位小數(shù)）

二、下面各題怎樣算簡便就怎樣算。（每題3分）

72.84-5.6+14.95.4X12.3+5.4X7.742

X101-42

0.25X3.2X12.53.64-1.54-2

33.4+0.12X50

22.7X1.25X0.83.91X2.8+6.09X2.8

5.5X17.3+6.7X5.5

1.5X1059.07—22.784-

3.43.8+4.29+2.1+4.2

0.25X0.79X45.6X3.9+4.4X

3.948X10.2

13.54-0.13X9.15.7?

0.19+15.63.65X2.4-6.36

70.3-17.484-7.63.644-52X

23.31.25X(6.2-5.9)X80

(9-4.1)4-(4.4+2.6)7.35X3.6+6.4X

7.3565.7X0.35-0.15

三、解下列方程（每題3分）

6x+15X7=1412x4-2.8=8.21.4x

-0.7x=56

5x+28=718.7-1.2x=3.9

8x-2.6x=37.8

0.75x-0.95X4=8.5544-

2+3x=728x-2.6=37.8

18.7-x=7.83X0.5+6x=3.3

X+4.8=7.2

12X-9X=8.76X+18=48

3(X+2.1)=10.5

15+5X=255X

1.8X=242X4-5.2=2.5

79X3+

3X=3572.4+3.4X=43.2

0.6(X-9)=12.6

1.4X+0.4X=362.5X+78=17X8

四、列式計算

1、36.8與8.8的差除5.6,商是多少？

2、一個數(shù)的2.5倍，比3.6多1.4,這個數(shù)是多少？

3、一個數(shù)乘上0.32的積比3的5倍少12.44,求這個數(shù)

4、6.75減去某數(shù)的5倍得2.75,求某數(shù).

5、一個數(shù)的3倍加上這個數(shù)的2倍等于1.5,求這個數(shù)。（列方

程解）

6、4.23加上0.72的和乘以3減去0.84的差，積是多少？（列綜

合算式計算）

7、甲數(shù)是2.89,比乙數(shù)的3倍少0.71,乙數(shù)是多少？

8、3.5與1.5的和除它們的差,商是多少?

五年級數(shù)學上冊口算題卡

小數(shù)乘法計算（1）

0.16X5=1.78X2.2=1.2X5=

0.7X0.01=2.5X0.4=1.25X8=

6.6X0.6=5.37X5=9.6X0.6=

123.9X7=53X2=55X3=

16.9X0.3=2.37+6.3=2.37+3.7=

2.5X1.25=4.4X25=2.64X5=

3.8X10.1=0.98X0.7=2.3X0.15=

0.78X5=5.3X4.2=5.24X0.99=

10.65X0.22=1X0.125=0.125X11=

4.39X10=0.1X4.39=0.7X23=

0.47X0.7=0.7X0.57=1.21X3=

12X0.03=3X0.121=8.6X0.7=

7.6X0.23=16.73X2.5=8.53X0.99=

7.3X5=5.8X0.29=5.8X2.9=

8.6X18=1.42X18=1.4X15=

五年級數(shù)學上冊口算題卡

小數(shù)乘法計算（2）

0.1X0.2=3.57X5=4.2X0.1=

99X0.35=0.05X0.8=1.23X3=

0.36X12=1.7X0.43=1.2X0.4=

7.5X2.5X4=0.4X1.3=5.43X0.86=

0.85X1.01=5.29X2.3=0.1X0.01=

0.28X35=4.68X4.5=0.25X0.5=

2.5X1.25=25.7X3.29=6.71X25.7=

6.5X56.5=1X0.85=4.73X3.9=

47.3X39=47.3X0.39=0.473X0.39=

2.4X5=1X1.25=0.45X0.09=

6.2X0.03=9X0.18=0.25X16=

0.125X0.125=0.7X8=9.9X2.5X4=

3.05X4=6.8X2=1.05X0.1=

4.2X21=5.64—2.1=1.25X80=

17.5X7.5X2=0.77X1.1=1.2—0.08=

五年級數(shù)學上冊口算題卡

小數(shù)乘法計算（3）

8-0.52=2.5X3.6=9.4X6=

5.08X0.92=1.2X3.6=1.4X1.2=

5.6X0.9=8.2X1.1=0.7X5=

3.5X1.6=0.27X0.036=0.1X250=

6.64X3.3=12.5X88=4.2X0.7X6=

10.2X35=5.6X3.5=7.2X48=

52X7.2=16.7-0.92-1.08=16.8+1.6=

1.8X4.5=3.8+5.6=0.7X4=

1.8+0.28=13.5X6=5.04X2.1=

22.6X0.33=3.25X0.98=0.75X0.5=

2.3X0.75=3.5X0.1=0.09X3.6=

200X0.04=12-1.2=1.3X0.5=

0.42X0.6=3.2X0.5=0.21X0.3=

2.5-1.37=5.5X2.15=10X0.56=

7.38X1.6=8.4X0.26=5.5X17.3=

五年級數(shù)學上冊口算題卡

小數(shù)乘法計算（4）

6.7X5.5=0.5X0.7=0.8X3.2=

1.5X4=5X4.8=0.75+0.8=

0.13X4=8.5X100=5.4X10=

4.2X1000=3.2X100=0.45X0.15=

3.6X0.1=0.18X0.3=1.2X0.3=

0.49X0.7=8.5X1.7=0.04X25=

9.782X3.2=53.73-17.49=8.76+0.351=

42.4+7.6=1.58+2.42=7.8-5.6=

1.25X4=7.8X0.5=3.9+2.7=

0.24X0.3=2.5X4=0.3X10=

1.25X8=5.7X5.7=0X4.8=

77X7.7=12-3.8=8.1-0.05=

0.24X0.3=0.2X0.5=2.5X3=

4.4X5X0.2=7X1.3=0.96X0.06=

0.36X0.3=0.35X0.7=8.89+0.1=

五年級數(shù)學上冊口算題卡

小數(shù)乘法計算（5）

4X8X1.25=13+0.7X0.7=0.8X0.25

4X0.5=7X2.1=1-0.12=

24X0.25=0.1X0.01=2.4X0.8=

9X0.4=10X0.01=30.2-3.02=

4.3-0.25=1-0.82=9.6X0.3=

2.6X0.01=0X25.4=4.8X0.2=

5.4+4.62=9-3.2=(1.5+2.4)X0.2=

1.7+1.3X0.4=3.6X23.6=8.5X0.5+0.6=

7.2X0.8=5.4X0.6=9.5X0.1=

10X2.5=35X0.05=0.64X0.4=

2.5X0.5=6.45X0.01=0.36X0.03=

0.08X0.001=0.01X0.2=7.5X2.5=

8.8X0.2=0.96X6=0.75X0.5=

0.7X5=0.08X1000=0.1X6.7=

1.6X0.5=2.5X4=0.74X0.4=

五年級數(shù)學上冊口算題卡

小數(shù)乘法計算（6）

7.5X3=3.74X0=0.8X0.6=

0.05X0.08=80X1.25=0.13X7=

3.5X4=2.8X0.5=3.5X200=

1.5—0.06=0.75X15=0.4X0.8=

4X0.25=0.36+1.54=1.01X99=

4204-42=17X40=100—63=

3.2+1.68=2.8X0.4=0.32X500=

0.65+4.35=10—5.4=3.5X200=

1.5—0.06=0.4X0.8=4X0.25=

1.01X99=0.1X6.7=0.08X1000=

1.6X0.5=2.5X0.4=7.5X3=

0.74X0.4=3.74X0=0.08X0.6=

0.005X8=80X1.25=0.13X7=

3.5X4=2.8X0.5=0.5X4=

8.2+2.6=7.16X0.4=125X0.8=

五年級數(shù)學上冊口算題卡

小數(shù)除法（1）

2.54-0.5=6.454-0.01=0.364-0.03=

0.084-0.01=0.014-0.2=7.54-2.5=

8.8+2.2=0.964-6=0.754-0.5=

2.6+2=9.64-4.8=3—1.5+2=

2.44-2=6.4—4=0.64-3+3=

0.914-13=3.25+0.75=0.94-0.1=

0.25X4=4.84-8=0.5+0.54-0.5=

50X0.8=10X0.05=0.13X7=

0.21X100=0.7X4=0.05X4=

4X0.3=12.5X8=2.3X4=

3.25X0=2.6X3=7.5X0.1=

0X9.8=1.254-0.25=34-4=

8.44-7=8.44-0.7=8.2+1.8=

30.44-4=0.344-0.17=0.724-0.6=

2.64-1.3=04-3.65=7.824-1=

五年級數(shù)學上冊口算題卡

小數(shù)除法（2）

0.0014-0.1=1.44-0.7=3.64-0.06=

5.64-0.9=5.64-1.4=0.484-0.8=

4.44-0.11=4.2X3=3.2X0.4=

0.34-0.01=44-0.5=5.14-1.7=

0.284-1.4=0.94-0.45=9.64-0.16=

14-0.01=0.014-1=7.54-1.5=

0.814-9=34-0.5=104-25=

6.44-0.16=04-3.89=3.524-0.01=

3.72X9.9+3.72=6.4+4=1.54-0.3=

1X0.44-1X0.4=384-1.9=6.424-2=

0.394-3=1.254-5=4.84-4=

1.8X5=7.24-3=2.2X6=

8.44-0.4=2.5X2.8=5.9-4.3=

0.85X0.5+4.6=5.9—4.3=94-5-94-5=

1.62X0.4+2.5=2.5X0.5-0.2=2.03X2-2.4=

五年級數(shù)學上冊口算題卡

小數(shù)混合計算（1）

1.65X0.5+0.5=0.9X0.4+0.8=4.2+5.8-3.4=

7.5-0.9=0X5.8=0.48+2X6=

0.36X0.9=1.62X0.4=2.5X0.5=

99X0.35=0.05X0.8=1.23X3=

0.36X12=7.5X2.5X4=1.2X0.4+1.3=

2.8X0.4=1.2X0.5-0.4=2.5X0.4=

1.2X5X8=5.37X0+4.63=1.6X2.4X0.3=

3.7X0.016=53X2.07=16.9X0.13=

2.03X2=44-0.5=7X2.1=

8.89+0.1=24X0.25=0.14-0.01=

2.4X0.8=9X0.4=10X0.01=

30.2-3.02=4.3-0.25=1-0.82=

9.6+0.3=2.6X0.01=0X25.4=

4.8X0.4=7.5X2.5X4=1.7+0.43+3.3=

1.2X0.4=5.24X0.99=10.654-0.22=

五年級數(shù)學上冊口算題卡

小數(shù)混合計算（2）

14-0.125=0.125X1=4.39X10=

4.394-0.1=0.7X2=0.7X0.7=

0.7+0.7=0.3X1.21=1.21X3=

1.58+2.42=7.8-5.6=1.25X4=

7.8X0.5=3.9+2.7=0.244-0.3=

2.5X4=0.34-10=1.25X8=

5.74-5.7=04-4.8=774-7.7=

12-3.8=8.1-0.05=16,734-2.5=

8.53X0.99=7.34-0.5=5.84-0.29=

5804-290=8.6X18+1.4=2.8X18=

(8.6+1.4)X18=0.1X0.2=3.5+7.5=

4.24-0.1=99X0.35=0.05X0.8=

1.234-3=0.364-12=8.5X100=

5.44-10=4.2X1000=24-100=

0.454-0.15=3.64-0.1=18X0.3=

五年級數(shù)學上冊口算題卡

綜合練習（1）

1.24-0.3=0.494-0.7=8.54-1.7=

0.04X25=9.7824-3.2=53.73-17.49=

8.76+0.351=42.4+7.6=6.454-0.01=

0.364-0.03=0.084-0.001=0.014-0.2=

7.54-2.5=8.84-0.2=0.964-6=

0.754-0.5=0.7X5=0.08X1000=

0.1X6.7=1.6X0.5=2.5X4=

0.74X0.4=7.5X3=0X25.4=

4.8X0.4=5.4+4.6X2.8=9-3.2X0.8=

1.7+1.3X0.4=(1.5+2.4)X0.2=1.7+1.3X0.4=

3.6X23.6=8.54-0.5+0.6=7.24-0.8=

5.4+0.6=9.54-0.1=104-2.5=

354-0.05=0.644-0.4=2.54-0.5=

3.2X0.5=0.21X0.3=2.5-1.37=

5.54-11=0.7X5=3.5X1=

五年級數(shù)學上冊口算題卡

綜合練習（2）

0.27X0.036=1?250=6.644-3.3=

1.82X0.7=0.5X32=3.24-0.8=

9.44-6=0.8X0.92=0.364-0.03=

5.5X2=4.84-8=4X7.5X2.5=

2.44-0.8=4.98+0.62=9.64-4.8=

3-1.5X2=2X3.1=2.4X0.5=

0.125X8-0.1=0.484-6=6.4-4=

0.64-3+3=0.914-13=3.25+0.75=

9.9-0.94-0.1=17X40=100-63=

3.2+1.68=0.5+0.5+0.5=50X0.8=

0.994-33=4.5X0.1=6.4+4=

1.3X7=24-0.4=2.1X404-10=

2.8X0.4=14-7.4=1.924-0.04=

0.4X0.8=4X0.2=1.7-0.47=

5-0.05=2.5X3=34-0.25=

五年級數(shù)學上冊口算題卡

綜合練習（3）

0.32X500=0.65+4.35=10-5.4=

4+20=3.5X200=1.5-0.06=

0.754-15=5.5X2=964-4.8=

3-1.5X2=3.1X5=5X2.4=

0.125X8-0.1=0.48+6=6.4-4=

0.6+3+3=0.91+1.3=3.25+0.75=

9.9_0.94-0.1=17X40=100-63=

3.2+1.68=4.84-8=0.5+0.54-5=

50X0.8=0.994-0.33=4X7.5X25=

4.5X0.1=2.44-8=1.3X7=

24-0.4=2.1X404-10=2.8X0.4=

14-7.4=1.924-0.04=0.4X0.8=

0.58+0.26=1.4X6=6.44-4=

4.98+0.62=1.7-0.47=5-0.05=

2.5X3=34-0.25=0.32X500=

五年級數(shù)學上冊口算題卡

綜合練習（4）

0.65+4.35=10-5.4=44-20=

3.5X200=1.5-0.06=0.754-15=

5.5X2=4X0.25=0.36+1.54=

1.01X99=4204-35=25X12=

1354-0.5=0.51+17=32.8+19=

5.24-1.3=1.6X0.4=4.9X0.7=

14-5=64-12=0.87-0.49=

3.5X0.1=434-0.1=200X0.04=

12-1.2=13X0.5=0.42+0.6=

6.34-7=0.21X0.3=5.694-0.5=

5.54-11=1.53-0.5=7.8+0.9=

7.5-2.5=124-0.4=0.56+4.44=

2.9+3.7+2.1=4X0.25=1.25X5X8=

7.6X8+2.4X8=1+0.1=0.4+0.42=

1-0.5=0.3+0.7=42.8-4.28=

五年級數(shù)學上冊口算題卡

綜合練習（5）

9.7-2=0.9-0.89=3.5+0.5=

5-0.64=6.3+7=7.2+2.8=

0.27-0.2=14-0.25X4=2.5X4

1.2X0.5=42.94-6=0.534-0.5=

0.34-0.1=14-0.5=1.4X11=

3.07X100=0.364-0.6=4.7+2.3=

4.5X2=6.9-2.5=7.2X0.8=

6X3.4=0.62-0.32=1.4X0.5=

0.75X100=0.02X0.5=3.64-0.3=

6.34-7=5.64-100=0.754-0.25=

0.125X8=4.84-0.3=0.964-20=

0.564-28=0.364-0.4=0.64+0.8=

0.724-3.6=3.64-24=0.8X1.1=

7.2+12.8=46.7-3.8=12.84-4=

5.24-13=12.54-5=1.644-41=

五年級數(shù)學上冊口算題卡

綜合練習（6）

8.44-0.01=1.94-19=0.15X0.4=

0.42X1.01=0.75X8=04-1.69=

0.64-10=1+0.25=0X3.7=

2.084-10=0.4X0.5=0.05X0.6=

1.7X3=3X2.2=7.6+4=

1.2X0.3=9.94-1.1=0.254-5=

0.254-0.05=0.15X0.4=0.05X6=

0.634-7=7.24-3.6=0.814-0.9=

4.3X0=0.3X0.16=64-12=

0.884-0.4=124-20=0.8100.3=

14-0.25=7X0.01=0.05X6=

0.02X0.03=0.814-3=1.06X5=

0.2X0.35=2.7X0.2=0.45X0.2=

1.5X6=0.05X0.8=2.4X0.2=

0.4X6=2.13X2=0.25X4=

五年級數(shù)學上冊口算題卡

綜合練習（7）

104-20=244-15=8.65X10=

0.35X0.6=3.08X0.01=4.95X1000=

6.9X0.1=0.4X0.5=2.44-0.8=

10.84-9=9.64-0.8=0.1084-2=

4.95+0.9=9.654-0.1=0.325X100=

2.5X8=0.564-0.7=0.125X4=

3.28X0.1=3.94-0.13=7.2X0.1=

0.01X0.1=0.25X0.4=1.64-0.8=

14-2.5=1.25X0.8=3.24-0.04=

04-1.7=0.22X102=9.698=

5X0.24=4.5-0.05=5.24-0.13=

16.54-0.5=5X0.12=0.5X24=

4.8X0.5=2.8+4.2=0.844-2.1=

3.8+5.6=14-0.001=2.7X0.3=

0.96X10=8.44-0.1=0.96X10=

五年級數(shù)學上冊口算題卡

小數(shù)的加法減法乘除法(1)

0.85-0.2=0.81-0.59=0.6-0.3=

0.81+9.6=0.57-0.1=0.98-0.3=

0.18+3.4=0.43+0.62=0.71-0.48=

0.44-0.3=0.18+3.9=0.64+0.81=

0.3+0.81=0.6-0.28=0.3+1.5=

0.8-0.7=0.29+0.4=0.31+0.61=

0.2+0.33=0.57+1=0.85+0.9=

0.84-0.16=0.33-0.11=0.81+5=

0.9+7.9=0.43+6.5=0.7+6.2=

0.8-0.21=0.99+1.1=0.85-0.6=

0.9+6.6=0.84-0.1=0.6-0.57=

0.49-0.1=0.51+2.8=0.68+0.9=

0.64-5.2=0.46+0.67=0.5+3.9=

0.874-8.7=4.44-0.5=3X2.4=

0.064-0.2=0.9X7.5=8.74-3=

8.44-1.4=0.3+3=0.824-8.2=

五年級數(shù)學上冊口算題卡

小數(shù)的加法減法乘除法（2）

2.84-5.6=1.894-2.1=0.9X0.4=

154-2.5=0.9X4.3=0.484-0.8=

1.464-7.3=7.764-9.7=7.3X0.2=

0.7X2.6=6X0.5=1.894-0.3=

0.084-0.1=9.9+3=5.1X3=

0.8X9.7=9.3X0.1=2.734-0.7=

3X6.4=3.5X6=0.724-7.2=

0.2X0.3=2.724-6.8=0.8X0.4=

0.5X4.3=4.1X6=0.2X2.1=

0.6X7-2=4—0.6X6=0.9X3-!=

3-0.4X3=0.5X9-1.5=4-1.2X3=

1.1X6-2.5=0.4X9-0.5=0.9X3-l=

0.9X6-1.5=0.8X4-1.5=0.7X4-0.5=

3.5-0.8X2=1.1X4-3=1.5-0.7X2=

0.6X8-4=0.5X5-2.5=1.1X8-4=

4-0.2X7=0.6X9-2=2-0.2X7=

五年級數(shù)學上冊口算題卡

小數(shù)的加減乘除法混合運算（1）

1.2+20+4=0.71+8.01-2.7=

57.2-1.9-48.1=1.2+1.2+4.8=

9.89-0.31-5.69=0.31+0.81+0.39=

5.01+0.2-0.07=0.09+0.14+0.41=

3.02+0.3-0.4=7.43-1.43+37.4=

0.62+7.02-4.6=6.21-1.21+8.65=

0.64-9+3.4=3.02+0.6-0.8=

3.04+0.5-0.8=8.51-4.51+54.7=

5.03+0.4-0.07=7.51-4.51+33.6=

7.79-0.61-6.39=1.04+0.5-0.6=

50.6-0.5-29.5=9.01-0.69-7.31=

64.6-0.7-29.3=45.4-0.1-9.9=

6.43-1.43+57.3=0.79+2+0.6=

5.21-1.21+8.24=0.65+8.05-6.6=

五年級數(shù)學上冊口算題卡

小數(shù)的加減乘除法混合運算（2）

5.01+0.4-0.05=0.37+0.4+0.33=

3.01+0.2-0.05=8.73-0.77-7.23=

7.8+1.9+2.1=1.03+0.5-0.07=

5.4+8.64-2.6=4.32-1.32+4.42=

66.6-0.1-49.9=7.61-5.61+2.46=

3.03+0.7-0.08=5.01+0.3-0.05=

0.02X5X0.9=2.5X0.6X0.4=

0.4X0.05X0.2=0.5X0.5X0.2=

0.3X0.25X0.4=0.5X0.6X0.2=

0.7X0.25X0.4=0.02X0.5X0.6=

0.02X0.005X0.6=0.02X5X0.4=

0.04X0.25X0.2=0.08X1.25X0.5=

0.02X0.05X0.5=0.04X0.25X0.7=

0.08X0.125X0.4=0.08X1.25X0.9=

五年級數(shù)學上冊口算題卡

小數(shù)的加減乘除法混合運算（3）

0.08X0.3X12.5=0.02X0.5X0.4=

0.8X1.25X0.7=0.02X0.5X0.8=

0.04X2.5X0.2=0.9X0.5X0.2=

0.8X0.125X0.8=0.08X1.25X0.8=

0.02X0.005X0.5=0.2X0.005X0.6=

0.02X0.05X0.7=5X0,7X0.2=

0.5X0.7X0.2=0.8X1.25X0.3=

0.02X0.5X0.3=0.02X5X0.2=

0.8X1.25X0.9=2.5X0.8X0.4=

0.02X0.5X0.7=0.02X0.005X0.2=

0.2X0.05X0.2=0.7X0.05X0.2=

0.5X0.25X0.4=0.02X0.005X0.3=

7X0.94-3.2=6+0.9X4.7=

4.2X0.2+3=9.4X0.4+5=

五年級數(shù)學上冊口算題卡

小數(shù)的加減乘除法混合運