Question

3.6×31.4 +43.9×6.4的简便算法

Answer 1

3.6×31.4 +43.9×6.4
=3.6×31.4 +(31.4+12.5)×6.4
=31.4*(3.6+6.4)+12.5*6.4
=31.4*10+(12.5*8)*(6.4/8)
=314+80
=394

Answer 2

3.6×31.4 +43.9×6.4
=(10-6.4)*31.4+43.9*6.4
=314+6.4*(43.9-31.4)
=314+6.4*12.5
=314+0.64*125
=314+(0.8*5)^2*5
=314+16*5
=394