速算题3题238÷238 238/23941 1/3*3/4+51 1/4*4/5+61 1/5*56-5/63.6*3

238÷238+238/239
=1+238/239
=477/239
41+1/3*3/4+51+1/4*4/5+61+1/5*5/6-5/6
=41+1/4+51+1/5+61+(1/5-1)*5/6
=41+1/4+51+1/5+61-2/3
=41+51+61+1/4+1/5-2/3
=153+(15+12-40)/60
=153-13/60
=(9180-13)/60
=9167/60
3.6*31.4+43.9*6.4
=(3+3/5)*(31+2/5)+(43+9/10)*(6+2/5)
=(93+6/5+93/5+6/25)+(258+86/5+27/5+9/25)
=(6/5+93/5+86/5+27/5)+(6/25+9/25)+(93+258)
=212/5+3/5+351
=43+351
=394

rge

一样看不明白··

看不明白