解题思路:(1)(2)(6)运用乘法分配律简算.
(3)把101看作100+1,运用乘法分配律简算.
(4)把3.2看作8×0.4,运用乘法结合律简算.
(5)运用除法的性质简算.
(1)1.2×0.5+3.5×1.2
=(0.5+3.5)×1.2
=4×1.2
=4.8
(2)3.5×0.7+5.5×0.7+0.7
=(3.5+5.5+1)×0.7
=10×0.7
=7
(3)6.2×101
=6.2×(100+1)
=6.2×100+6.2
=620+6.2
=626.2
(4)0.125×3.2
=0.125×8×0.4
=(0.125×8)×0.4
=1×0.4
=0.4
(5)21÷0.25÷0.4
=21÷(0.25×0.4)
=21÷0.1
=210
(6)0.83×101-0.83
=0.83×(101-1)
=0.83×100
=83
点评:
本题考点: 小数四则混合运算.
考点点评: 注意观察题目中数字构成的特点和规律,善于灵活运用运算定律或运算技巧,进行简算.