9.9×2.3 12.5×0.8×4×0.5 2.5×0.32×1.25 5.3×10.1 简便计算,要有列式.
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9.9×2.3 12.5×0.8×4×0.5 2.5×0.32×1.25 5.3×10.1 简便计算,要有列式.
![9.9×2.3 12.5×0.8×4×0.5 2.5×0.32×1.25 5.3×10.1 简便计算,要有列式.](/uploads/image/z/15051709-37-9.jpg?t=9.9%C3%972.3+12.5%C3%970.8%C3%974%C3%970.5+2.5%C3%970.32%C3%971.25+5.3%C3%9710.1+%E7%AE%80%E4%BE%BF%E8%AE%A1%E7%AE%97%2C%E8%A6%81%E6%9C%89%E5%88%97%E5%BC%8F.)
9.9×2.3
=(10-0.1)×2.3
=10×2.3-2.3×0.1
=23-0.23
=22.77
12.5×0.8×4×0.5
=(12.5×0.8)×(4×0.5)
=10×2
=20
2.5×0.32×1.25………变一变,就简便.
=(2.5×0.4)×(0.8×1.25)
=1×1
=1
5.3×10.1………变一变,就简便
=5.3×(10+0.1)
=5.3×10+5.3×0.1
=53+0.53
=53.53
=(10-0.1)×2.3
=10×2.3-2.3×0.1
=23-0.23
=22.77
12.5×0.8×4×0.5
=(12.5×0.8)×(4×0.5)
=10×2
=20
2.5×0.32×1.25………变一变,就简便.
=(2.5×0.4)×(0.8×1.25)
=1×1
=1
5.3×10.1………变一变,就简便
=5.3×(10+0.1)
=5.3×10+5.3×0.1
=53+0.53
=53.53