計算下面各題(能簡算的要簡算)
65×101
972-(282+27×9)
(4+40)×25
287-99
32×125
34×55+67×55-55.
解:(1)65×101,
=65×100+65,
=6500+65,
=6565;
(2)972-(282+27×9),
=972-282-243,
=690-243,
=447;
(3)(4+40)×25,
=4×25+40×25,
=100+1000,
=1100;
(5)32×125,
=4×(8×125),
=4×1000,
=4000;
(6)34×55+67×55-55,
=(34+67-1)×55,
=100×55,
=5500.
分析:(1)65×101,運用乘法分配律進行簡算;
(2)972-(282+27×9),運用減法的運算性質(zhì)進行簡算;
(3)(4+40)×25,運用乘法分配律進行簡算;
(4)287-99,轉(zhuǎn)化為287-100+1計算簡便;
(5)32×125,轉(zhuǎn)化為4×8×125,再運用乘法結(jié)合律進行簡算;
(6)34×55+67×55-55,運用乘法分配律進行簡算.
點評:此題考查的目的是熟練掌握運算定律和運算性質(zhì),能夠靈活選擇簡便方法進行計算.