Question

数学简算（用乘法分配律、乘法结合律、乘法交换律计算）能用哪个就用那个，能简算简算，不能就脱式计算

1、2.5×0.6－1.8×0.5 2、3.25×4.76－7.8 3、（4＋0.4）×0.25 4、12.5×12×8 5、50×1.13×0.2 6、14.7×1.5×2.8 7、2.63×0.8＋2.63×0.2 8、3.5×1.83－0.83×3.5

Answer 1

1、2.5×0.6－1.8×0.5 =0.5*5*0.6-1.8*0.5=0.5(5*0.6-1.8)=0.5(3-1.8)=0.5(1.2)=0.6

2、3.25×4.76－7.8 =7.67

3、（4＋0.4）×0.25 =（4×0.25 ＋0.4×0.25 ）=1+0.1=1.1

4、12.5×12×8 =12.5*8*12=100*12=1200

5、50×1.13×0.2=50×0.2×1.13=10*1.13=11.3

6、14.7×1.5×2.8 =61.74

7、2.63×0.8＋2.63×0.2 =2.63×(0.8＋0.2)=2.63*1=2.63

8、3.5×1.83－0.83×3.5=3.5×(1.83－0.83)=3.5*1=3.5

追问

简算，要过程，要分行的分行

追答

1、2.5×0.6－1.8×0.5
=(0.5*5)*0.6-1.8*0.5
=0.5*(5*0.6)-1.8*0.5
=0.5(5*0.6-1.8)
=0.5(3-1.8)
=0.5(1.2)
=0.6

2、3.25×4.76－7.8 =7.67

3、（4＋0.4）×0.25
=（4×0.25 ＋0.4×0.25 ）
=1+0.1
=1.1

4、12.5×12×8
=12.5*8*12
=100*12
=1200

5、50×1.13×0.2
=50×0.2×1.13
=10*1.13=11.3

6、14.7×1.5×2.8 =61.74

7、2.63×0.8＋2.63×0.2
=2.63×(0.8＋0.2)
=2.63*1
=2.63

8、3.5×1.83－0.83×3.5
=3.5×(1.83－0.83)
=3.5*1
=3.5