Question

口算．

44× 2 11 =	3- 1 3 =	2.1+3.4=	3.5÷1000=	136萬(wàn)+3.4萬(wàn)=
3 7 ÷ 3 8 =	1 a - 1 b =	91÷ 1 1000 × 1 1000 =	9π≈	63.2÷8.1≈

Answer 1

分析：①約分計(jì)算；②把3化成分母為3的分?jǐn)?shù)，再計(jì)算；③小數(shù)點(diǎn)對(duì)齊；④把3.5的小數(shù)點(diǎn)向左移動(dòng)三位；⑤小數(shù)點(diǎn)對(duì)齊，同時(shí)注意不要忘記帶單位名稱；⑥把除法改為乘法，約分計(jì)算；⑦通分計(jì)算；⑧按運(yùn)算順序從左往右依次運(yùn)算；⑨取π=3.14，計(jì)算后用四舍五入法保留整數(shù)；⑩計(jì)算后用四舍五入法保留整數(shù)．

解答：解：44×

2

11

=8；    3-

1

3

=2

2

3

；       2.1+3.4=5.5；       3.5÷1000=0.0035；       136萬(wàn)+3.4萬(wàn)=139.4萬(wàn)；

3

7

÷

3

8

=

8

7

；        

1

a

-

1

b

=

b-a

ab

；   91÷

1

1000

×

1

1000

=91；     9π≈28；        63.2÷8.1≈78．

點(diǎn)評(píng)：此題考查了多方面的知識(shí)，根據(jù)題目特點(diǎn)，靈活解答．