Question

每题都要有必要的计算过程．
①23×2424-24×2323
②52.44×79.45+159×47.56+79.55×52.44
③18×

3

7

+0.65×

8

13

-

2

7

×18+

5

13

÷1

7

13

④2.75+

5

12

-1.4+2

1

4

÷

5

12

-87.5%
⑤

2010×2008+1

2009

+

2009+2010×2008

2009×2010-1

．

Answer 1

①23×2424-24×2323
=23×24×101-24×23×101
=0；

②52.44×79.45+159×47.56+79.55×52.44
=52.44×（79.45+79.55）+159×47.56
=52.44×159+159×47.56
=159×（52.44+47.56）
=159×100
=15900；

③18×

3

7

+0.65×

8

13

-

2

7

×18+

5

13

÷1

7

13

=

54

7

+

2

5

-

32

7

+

1

4

=（

54

7

-

32

7

）+（

2

5

+

1

4

）
=3

1

7

+

13

20

=3

111

140

；

④2.75+

5

12

-1.4+2

1

4

÷

5

12

-87.5%
=2.75+

5

12

-1.4+5.4-87.5%
=3

1

6

-1.4+5.4-87.5%
=3

1

6

+4-87.5%
=6

7

24

；

⑤

2010×2008+1

2009

+

2009+2010×2008

2009×2010-1

=

2009×2008+2008+1

2009

+

2009+2008×2009+2008

2009×(2009+1)-1

=

2009×(2008+1)

2009

+

2009×(2008+1)+2008

2009×2009+2008

=2009+1
=2010．