①36×
-15×25%-0.25,1 4
=36×0.25-15×0.25-0.25,
=(36-15-1)×0.25,
=20×0.25,
=5;
②15.8-
+14.2-7 18
,11 18
=(15.8+14.2)-(
+7 18
),11 18
=30-1,
=29;
③(1+
)÷(1-1 3
),1 3
=
÷4 3
,2 3
=
×4 3
,3 2
=2;
④2.5×3.2×12.5,
=2.5×4×0.8×12.5,
=(2.5×4)×(0.8×12.5),
=10×10,
=100.