5.61-
+4.39-1
3.74×5.8+62.6×0.58
(
-
)+(
-
)+(
-
)+(
-
)+(
-
)解:(1)5.61-
+4.39-1
,=(5.61+4.39)-(
+1
),=10-2,
=8;
(2)3.74×5.8+62.6×0.58,
=3.74×5.8+6.26×5.8,
=(3.74+6.26)×5.8,
=10×5.8,
=58;
(3)(
-
)+(
-
)+(
-
)+(
-
)+(
-
),=(
+
+
+
+
)-(
+
+

),=

,=1
,=
.分析:(1)把5.61-
+4.39-1
改写成(5.61+4.39)-(
+1
),从而简算;(2)把3.74×5.8+62.6×0.58改写成3.74×5.8+6.26×5.8,再逆用乘法分配律简算;
(3)把(
-
)+(
-
)+(
-
)+(
-
)+(
-
)改写成(
+
+
+
+
)-(
+
+

),从而简算得解.点评:完成本题要注意分析式中数据和运算符号,运用合适的简便方法计算.