脱式计算.(能简算的要简算) (1)1/43+303/8686+90909/434343+131313/868686 (2)6.75−2.75÷[10×(9.75−41/4)] (3)0.365×640+31/2×36.5+365×0.01

问题描述:

脱式计算.(能简算的要简算)
(1)

1
43
+
303
8686
+
90909
434343
+
131313
868686

(2)6.75−2.75÷[10×(9.75−4
1
4
)]

(3)0.365×640+3
1
2
×36.5+365×0.01

(1)

1
43
+
303
8686
+
90909
434343
+
131313
868686

=
1
43
+
3×101
86×101
+
9×10101
43×10101
+
13×10101
86×10101

=
1
43
+
3
86
+
9
43
+
13
86

=(
1
43
+
9
43
)+(
3
86
+
13
86
),
=
10
43
+
8
43

=
18
43

(2)6.75-2.75÷[10×(9.75-4
1
4
)],
=6.75-2.75÷[10×(9.75-4.25)],
=6.75-2.75÷[10×5.5],
=6.75-2.75÷55,
=6.75-0.05,
=6.7;     
(3)0.365×640+3
1
2
×36.5+365×0.01,
=36.5×6.4+3.5×36.5+36.5×0.1,
=36.5×(6.4+3.5+0.1),
=36.5×10,
=365.