作业帮 > 数学 > 作业

用简便方法计算 1.4*56.8+4.32*14 2000*199.9-1999*199.8 312.5*12.3-31

来源:学生作业帮 编辑:百度作业网作业帮 分类:数学作业 时间:2024/05/06 04:16:40
用简便方法计算 1.4*56.8+4.32*14 2000*199.9-1999*199.8 312.5*12.3-312.5*6.9+312.5
9.56*4.18-7.3*4.18-0.26*4.18
1.4*56.8+4.32*14 2000*199.9-1999*199.8 312.5*12.3-312.5*6.9+312.5
9.56*4.18-7.3*4.18-0.26*4.18从打一遍
用简便方法计算 1.4*56.8+4.32*14 2000*199.9-1999*199.8 312.5*12.3-31
1.4*56.8+4.32*14
=14*5.68+4.32*14
=14*(5.68+4.32)
=14*10
=140
2000*199.9-1999*199.8
=2000*(199.8+0.1)-1999*199.8
=2000*199.8+2000*0.1-1999*199.8
=(2000-1999)*199.8+2000*0.1
=199.8+200
=399.8
312.5*12.3-312.5*6.9+312.5
=312.5*(12.3-6.9+1)
=312.5*6.4
=(25*4)*2*(12.5*0.8)
=100*2*10
=2000
9.56*4.18-7.3*4.18-0.26*4.18
=(9.56-7.3-0.26)*4.18
=2*4.18
=8.36