问题
解答题
下面各题,怎样简便怎样算. (1)199+99×99 (2)75÷4+24×
(3)35.4-2.76+64.6+7.24 (4)(
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答案
(1)199+99×99
=199+99×(100-1),
=199+99×100-99×1,
=199+9900-99,
=199-99+9900,
=100+9900,
=10000;
(2)75÷4+24×
+1 4 1 4
=75×
+24×1 4
+1 4
,1 4
=(75+24+1)×
,1 4
=100×
,1 4
=25;
(3)35.4-2.76+64.6+7.24
=35.4+64.6-2.26+7.24,
=100-2.26+7.24,
=97.74+7.24,
=104.98;
(4)(
+0.2)÷0.25×250%3 4
=(0.75+0.2)×250%÷0.25,
=0.95×(2.5÷0.25),
=0.95×10,
=9.5.