Question

求解五年级简便运算

5.7×10.1
0.279×355＋0.645×279

Answer 1

5.7×10.1
乘法的分配率
=5.7×（10+0.1）
=5.7×10+5.7×0.1
=57+0.57
=57.57

0.279×355+0.645×279
=279×0.355+0.645×279
乘法的结合律
=279×（0.355+0.645）
=279×1
279

Answer 2

5.7*(10+0.1)
=57+0.57
=57.57

0.279*355+645*0.279
=0.279*(355+645)
=0.279*1000
=279

Answer 3

5.7×10.1=5.7×(10+0.1)=57+0.57=57.57
0.279×355＋0.645×279
=279×3.55＋0.645×279
=279(3.55+0.645)
=279

Answer 4

5.7×10.1
=5.7x(10+0.1)
=5.7x10+5.7x0.1
=57+0.57
=57.57
0.279×355＋0.645×279
=279x0.355+0.645x279
=279x(0.355+645)
=279x1
=279

Answer 5

5.7×1（10+0.1）=5.7×10+5.7×0.1=57+0.57=57.57