| 125×8.8 | 1.3+4.25+3.7+3.75 | 4.8×1.01 |
| 17.16-(3.5-2.85) | 3.4×99+3.4 | ![]() |
![]() | ![]() | 64.2×87+64.2×13. |
=125×8×1.1,
=1000×1.1,
=1100;
(2)1.3+4.25+3.7+3.75,
=(1.3+3.7)+(4.25+3.75),
=5+8,
=13;
(3)4.8×1.01,
=4.8×1+4.8×0.01,
=4.8+0.048,
=4.848;
(4)17.16-(3.5-2.85),
=17.16+2.85-3.5,
=20.01-3.5,
=16.51;
(5)3.4×99+3.4,
=3.4×(99+1),
=3.4×100,
=340;
(6)
,=(
)×17,=1×17,
=17;
(7)
,=
,=28
,=28
;(8)
,=(
)×
,=1×
,=
;(9)64.2×87+64.2×13.
=64.2×(87+13),
=64.2×100,
=6420.
分析:根据减法是运算性质、加法和乘法的运算定律进行简算.
点评:此题考查的目的是理解掌握减法的运算性质、加法、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.