解:(1)52.3×0.9+5.23,
=5.23×9+5.23,
=5.23×(9+1),
=5.23×10,
=52.3;
(2)0.01+1.01×99,
=0.01+1.01×(100-1),
=0.01+1.01×100-1.01×1,
=101+0.01-1.01,
=100;
(3)0.7777×0.7+0.1111×5.1.
=0.1111×4.9+0.1111×5.1,
=0.1111×(4.9+5.1),
=0.1111×10,
=1.111.
分析:(1)52.3×0.9+5.23,將原式轉(zhuǎn)化為:5.23×9+5.23,運(yùn)用乘法分配律進(jìn)行簡(jiǎn)算;
(2)0.01+1.01×99,應(yīng)把99分解成(100-1),運(yùn)用乘法分配律進(jìn)行簡(jiǎn)算;
(3)0.7777×0.7+0.1111×5.1.首先根據(jù)因數(shù)與積的變化規(guī)律,將原式轉(zhuǎn)化為:0.1111×4.9+0.1111×5.1,再運(yùn)用乘法分配律進(jìn)行簡(jiǎn)算.
點(diǎn)評(píng):這三道題都是通過把一個(gè)數(shù)進(jìn)行合理的變形,間接地利用乘法的分配律去計(jì)算.