Question

用简便计算。2.02x8.5 1.25+4.6+0.75 1.6x7.5x1.25

用简便计算。2.02x8.5 1.25+4.6+0.75 1.6x7.5x1.25 56x1.25 3.4x7x1.5 0.8x0.25x0.4x12.5

Answer 1

2.02x8.5

=（2+0.02）*8.5
=2*8.5+0.02*8.5
=17+0.17
=17.17
1.25+4.6+0.75
=（1.25+0.75）+4.6
=2+4.6
=6.6
1.6x7.5x1.25

=0.8*2*7.5*1.25
=（0.8*1.25）*（2*7.5）
=1*15
=15
56x1.25

=7*（8*1.25）
=7*10
=70
3.4x7x1.5

= 3.4*（7*1.5）
= 3.4*10.5
=3.4*（10+0.5）
=3.4*10+3.4*0.5
=34+1.7
=35.7
0.8x0.25x0.4x12.5

=（0.8*12.5）*（0.25*0.4）
=10*0.1
=1

Answer 2