It depends on assignment I have to work on, for example when I was working on tool development assignment , I have to read almost 100 articles and that number of articles were more than as compare to my research thesis.
In my opinion, I think it's not about how many articles I should read per month. But it's about the subject or the research I'm working on. You may be going through a month without 10 articles reading (because there is no plan for research at that time).
On the other hand, you may need in a certain month to read 100 articles because you are preparing to publish a paper in that period. However, the researcher must be persistent in reading even if he has no research to continue to develop himself.
Through the answers of most colleagues, I see that reading of certain number of articles is related to the time factor but for others it is related to the need of reading (for example: Hidouri Khaoula' answer). Also, Some colleagues are committed to reading a fixed number every month.
There are no set magical numbers. It depends largely where you are in your research. If you are in the staring phase may be you will read on an average 1 per day. As you get clearer as to what you want to do with your research the rate may come down to perhaps 2 per week.
I am closely attached with one journal. In some month, I check 50 -60 papers! But all can not satisfy me.
The number for me is 0- 70 papers per month for the journal.
But for my own publication, there is no limit. For preparation of my latest publication, a review article of 54 pages published in a journal of Benthumscience group, I read a huge number of papers for 6 - 7 months.
It depends on the work you do, sometimes you read ten papers and in others you read a hundred papers as in the discussions of Master's and Doctor's thesis.
I have never counted how many articles I read per month. Now I am preparing new study and I have free time. Since 25.07 I have read 45 papers, about 2-3 per day. The topic is new for me, therfore I am not able to read and understand more than three scientific papers per day.
During the semester I do not have too much free time and I read about 1-2 papers per week, sometimes 3.
Ultimately goal of research to find out or discover the truth and give it a public platform.
Tht needs not only number of researches to read but also the applied aspects of concepts tht establishes and enhances a level of understanding.
Improves knowledge
Solves the mistakes
And make others to learn from
If one knows wht he or she exactly wants to understand/know... The satisfactory efforts are needed to put in.. then however more or less numbers of research works are needed to read may not remain an issue..