1/51+1/52+1/53+.+1/59+1/60
＜1/50+1/50+1/50+1/50+1/50+1/50+1/50+1/50+1/50+1/50
=1/50×10
=1/5
=0.2
∴0＜1/51+1/52+1/53+.+1/59+1/60＜0.2
∴整数部分是 0