(1)450÷18×25+173,
=25×25+173,
=625+173,
=798;
(2)670+65÷3×
,3 5
=670+65×(
×1 3
),3 5
=670+65×
,1 5
=670+13,
=683;
(3)
-5 8
×1 6
+57,4 5
=
-5 8
+57,2 15
=
+57,59 120
=57
;59 120
(4)38-12×6÷16,
=38-72÷16,
=38-4.5,
=33.5.