问题
解答题
计算下面各题,能简算的要简算.
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答案
(1)102×4.5,
=(100+2)×4.5,
=100×4.5+2×4.5,
=450+9,
=459;
(2)7.8×6.9+2.2×6.9,
=6.9×(7.8+2.2),
=6.9×10,
=69;
(3)5.6×1.25,
=0.7×(8×1.25),
=0.7×10,
=7.
计算下面各题,能简算的要简算.
|
(1)102×4.5,
=(100+2)×4.5,
=100×4.5+2×4.5,
=450+9,
=459;
(2)7.8×6.9+2.2×6.9,
=6.9×(7.8+2.2),
=6.9×10,
=69;
(3)5.6×1.25,
=0.7×(8×1.25),
=0.7×10,
=7.