分析:(1)根据加法结合律进行简算;
(2)17.625减去4.4与7
的和,等于分别减去4.4与7
;
(3)根据乘法分配律进行简算;
(4)把48拆成6×8,再根据乘法交换律和结合律进行简算;
(5)5÷17=
,
×4=
,再根据连续减去两个数,等于减去这两个数的和进行简算;
(6)根据乘法分配律进行简算.
解答:解:(1)1.7+5
+3.98,
=1.7+(5
+3.98),
=1.7+9,
=10.7;
(2)17.625-(4.4+7
),
=17.625-4.4-7
,
=17.625-7
-4.4,
=10-4.4,
=5.6;
(3)3.35×6.4×2+6.7×3.6,
=(3.35×2)×6.4+6.7×3.6,
=6.7×6.4+6.7×3.6,
=6.7×(6.4+3.6),
=6.7×10,
=67;
(4)0.25×48×1.25,
=0.25×(6×8)×1.25,
=(0.25×6)×(8×1.25),
=1.5×10,
=15;
(5)3.34-5÷17-
×4,
=3.34-
-
,
=3.34-(
+
),
=3.34-1,
=2.34;
(6)
-(
-
)×9,
=
-(
×9-
×9),
=
-
+
,
=
.
点评:根据题意,找清运用的运算定律,然后再进一步计算即可.