9 -( + ) | 1.8× +2.2×25% | 6.9×99+6.9 | 67×101 |
| 2.5×32×0.125 | - + -![]() | 10000÷125÷8 | 105×( + + ) |
-(
+
),=
,=9
,=
;(2)1.8×
+2.2×25%,=(1.8+2.2)×0.25,
=4×0.25,
=1;
(3)6.9×99+6.9,
=6.9×(99+1),
=6.9×100,
=690;
(4)67×101,
=67×100+67×1,
=6700+67,
=6767;
(5)2.5×32×0.125,
=(2.5×4)×(8×0.125),
=10×1,
=10;
(6)
-
+
-
,=
(
),=1-1,
=0;
(7)10000÷125÷8,
=10000÷(125×8),
=10000÷1000,
=10;
(8)105×(
+
+
),=105×
105×
105×
,=35+21+15,
=71.
分析:(1)9
-(
+
),根据减法的运算性质进行简算;(2)1.8×
+2.2×25%,运用乘法分配律进行简算;(3)6.9×99+6.9,运用乘法分配律进行简算;
(4)67×101,运用乘法分配律进行简算;
(5)2.5×32×0.125,运用乘法结合律进行简算;
(6)
-
+
-
根据加、减法的运算性质进行简算;(7)10000÷125÷8,根据除法的运算性质进行简算;
(8)105×(
+
+
),运用乘法分配律据此简算.点评:此题考查的目的是掌握减法的运算性质、乘法的运算定律,并且能够灵活运用这些运算性质和运算定律进行简便计算.