(1)365+289+135
=365+135+289
=500+289
=789;
(2)
+2 3
×7 9
3 14
=
+2 3
1 6
=
;5 6
(3)
×17 8
-3 5
×12.5%3 5
=(
-12.5%)×17 8
3 5
=2×
3 5
=
;6 5
(4)20-
-8 25
7 25
=20-(
+8 25
)7 25
=20-
3 5
=19
;2 5
(5)3.8×99+3.8
=3.8×(99+1)
=3.8×100
=380;
(6)4×0.27×25
=4×25×0.27
=100×0.27
=27.