你是要估算?
估算的话
(1+0.25)^5
=1+5x0.25+10X0.25^2+10x0.25^3
=1+1.25+2x1.25/4+10x0.25^3
=2.25+0.625+0.625/4
=2.875+0.15625
=3.03125
偏差在小数点后2位
直接算 就是
1+5/4+10/16+10/64+5/256+1/1024
=1+1.25+0.625+0.15625+0.01953125+0.0009765625
=3.051757813
或者 变成分数形式计算
（5/4)^5
=3125/1024 约等于3.1
=3.051757813