AttributeError: 'Series' object has no attribute 'rolling', pandas

Question

This is the code:

%matplotlib inline
from pylab import mpl,plt
import quandl as q

plt.style.use('ggplot')
mpl.rcParams['font.family']='serif'


q.ApiConfig.api_key='7QRLThQTiHp5Xp-tFlk'

d=q.get('BCHAIN/MKPRU') 

d['SMA']=d['Value'].rolling(100).mean()

And this is the error I get:

AttributeError: 'Series' object has no attribute 'rolling'

I am using pandas 0.18.1