解:(1)200-199+198-197+196-195+…+4-3+2-1,
=(200-199)+(198-197)+(196-195)+…+(4-3)+(2-1),
=1×100,
=100;
(2)

×

+

×

+

×

+…+

×

,
=

-

+

-

+

-

+…+

-

,
=

-

,
=

;
(3)1.8+62=63.8;
(4)44÷

,
=44×

,
=40;
(5)2.4×5,
=(2+0.4)×5,
=2×5+0.4×5,
=10+2,
=12;
(6)1÷

+

÷1,
=1×10+

,
=10

;
(7)

÷

,
=

,
=

;
(8)3.4-1

,
=3.4-1.6,
=1.8;
(9)2-1

,
=2-(1

-

),
=2-1

,
=

;
(10)

+

+

+…+

,
=(1-

)+(

-

)+(

-

)+…+(

-

),
=1-

+

-

+

-

+…+

-

,
=1-

,
=

;
(11)8.8×(

+

+

),
=8.8×

+8.8×

+8.8×

,
=3.2+5.5+6.6,
=15.3;
(12)0.75×16+

,
=0.75×16+0.75×5-0.75,
=(16+5-1)×0.75,
=20×0.75,
=15;
(13)98÷

,
=98×

,
=(99-1)×

,
=99×

-

,
=98-

,
=97

;
(14)30

-(18.8+12×

),
=30.6-(18.8+9),
=30.6-27.8,
=2.8.
分析:(1)此題可以運加法結(jié)合律計算,共有100個1相加;
(2)算出每項兩個分?jǐn)?shù)相乘的積,然后把每個分?jǐn)?shù)拆成兩個分?jǐn)?shù)相減的形式,通過加減相互抵消,得出結(jié)果;
(3)注意小數(shù)點對齊,整數(shù)與整數(shù)部分相加,小數(shù)與小數(shù)部分相加;
(4)(7)題,除以一個數(shù)等于乘這個數(shù)的倒數(shù),注意約分;
(5)把2.4看作2+0.4,運用乘法分配律簡算;
(6)按運算順序計算,先算除法,再算加法;
(8)把分?jǐn)?shù)化為小數(shù),在計算時注意小數(shù)點對齊;
(9)運用減法的性質(zhì)簡算;
(10)把每個分?jǐn)?shù)拆成兩個分?jǐn)?shù)相減的形式,通過加減相互抵消,得出結(jié)果;
(11)根據(jù)數(shù)字特點,運用乘法分配律簡算;
(12)把分?jǐn)?shù)化為小數(shù),然后運用乘法分配律的逆運算簡算;
(13)把除法改為乘法,把98看作99-1,然后運用乘法分配律簡算;
(14)按運算順序計算,先算括號內(nèi)的,再算括號外的,同時注意數(shù)的轉(zhuǎn)化.
點評:此題考查了學(xué)生對四則混合運算順序的掌握以及簡算的能力,要注意根據(jù)數(shù)的特點對整數(shù)分?jǐn)?shù)進行拆項和裂項.