分析:(1)689+194,根據(jù)加法的運(yùn)算性質(zhì)進(jìn)行簡算;
(2)624-297,根據(jù)減法的運(yùn)算性質(zhì)進(jìn)行簡算;
(3)785-184-216,根據(jù)減法的運(yùn)算性質(zhì)進(jìn)行簡算;
(4)451-202,根據(jù)減法的運(yùn)算性質(zhì)進(jìn)行簡算;
(5)234+187+66,運(yùn)用加法的交換律和結(jié)合律進(jìn)行簡算;
(6)563-(263+154),根據(jù)減法的運(yùn)算性質(zhì)進(jìn)行簡算.
解答:解:(1)689+194,
=689+200-6,
=883;
(2)624-297,
=624-300+3,
=327;
(3)785-184-216,
=785-(184+216),
=785-400,
=385;
(4)451-202,
=451-200-2,
=249;
(5)234+187+66,
=187+(234+66),
=187+300,
=487;
(6)563-(263+154),
=563-263-154,
=300-154,
=146.
點(diǎn)評:此題考查的目的是使學(xué)生靈活運(yùn)用加法的運(yùn)算定律和加、減法的運(yùn)算性質(zhì)進(jìn)行簡便計(jì)算.