一道简算题六年级滴

问题描述:

一道简算题六年级滴
2/2*4 * 2/4*6 + 2/6*8 + 2/8*10 + 2/10*12

2/2*4 * 2/4*6 + 2/6*8 + 2/8*10 + 2/10*12=2/2(1/1*2+1/2*3+1/3*4+1/4*5+1/5*6)=1/1*2+1/2*3+1/3*4+1/4*5+1/5*6=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6=1-1/6=5/6