解题思路:(1)先去掉括号,再计算;
(2)运用乘法分配律简算;
(3)运用乘法结合律简算;
(4)把分子和分母都运用乘法分配律简算,然后再化简;
(5)1-[1/2×2]=1-[1/4]=[3/4]=[1/2]×[3/2];
1-[1/3×3]=1-[1/9]=[8/9]=[2/3]×[4/3];
…
由此化简求解.
(1)7[4/15]-(2[4/15]-2.3),
=7[4/15]-2[4/15]+2.3,
=5+2.3,
=7.3;
(2)4.85×3[3/5]-3.6+6.15×3[3/5],
=4.85×3.6-3.6+6.15×3.6,
=(4.85-1+6.15)×3.6,
=10×3.6,
=36;
(3)0.025×999×2.8×40÷2[4/5],
=(0.025×40)×(2.8÷2.8)×999,
=1×1×999,
=999;
(4)[2001×2001+2001/2002×2002−2002],
=
2001×(2001+1)
2002×(2002−1),
=[2001×2002/2002×2001],
=1;
(5)(1-[1/2×2])(1-[1/3×3])(1-[1/4×4])…(1-[1/2001×2001]),
=([1/2]×[3/2])×([2/3]×[4/3])×([3/4]×[5/4])×…([2000/2001]×[2002/2001]),
═[1/2]×([3/2]×[2/3])×([4/3]×[3/4])×…([2001/2000]×
点评:
本题考点: 分数的四则混合运算;运算定律与简便运算;分数的简便计算;小数四则混合运算;分数的巧算.
考点点评: 此题考查四则混合运算,要仔细观察算式的特点,灵活运用一些定律进行简便计算;较复杂的计算要先找出规律,然后根据规律化简求解.