脱式计算(能简算的要简算)6.5×99 0.7×9.2+0.7×0.8.
第1个回答 2014-10-24
(1)6.5×99,
=6.5×(100-1),
=6.5×100-6.5×1,
=650-6.5,
=643.5;
(2)0.7×9.2+0.7×0.8,
=0.7×(9.2+0.8),
=0.7×10,
=7.
=6.5×(100-1),
=6.5×100-6.5×1,
=650-6.5,
=643.5;
(2)0.7×9.2+0.7×0.8,
=0.7×(9.2+0.8),
=0.7×10,
=7.