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.

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/12 19:06:50

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.

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
=(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

12.5乘4.86乘0.4 =12.5*2.43*0.8 =(12.5*0.8)*2.43 =10*2.43 =24.3 12.5×4.86×0.4=12.5×0.4×2×2.43=10×2...