解:
(1)

÷(3-

-

),
=

÷[3-(

+

)],
=

÷[3-1],
=

÷2,
=

;
(2)

×13+

×5,
=

×13+

×11,
=

×(13+11),
=

×24,
=10;
(3)375+450÷18×25,
=375+25×25,
=375+625,
=1000;
(4)

+

÷(4÷

),
=

+

÷6,
=

+

,
=1.
分析:(1)3连续减去

与

,等于减去

与

的和,最后算除法;
(2)根据乘法分配律进行简算;
(3)先算除法,再算乘法,最后算加法;
(4)先算小括号里面的除法,再算小括号外面的除法,最后算加法.
点评:四则运算,先弄清运算顺序,然后再进一步计算,能简算的要简算.