There is no set number of views needed for Google Adsense approval. However, generally speaking, you will need to have a decent amount of traffic before you can be approved for the program. This is because advertisers want to know that their ads will be seen by a lot of people, and so they are more likely to approve your application if you can show that you have a good amount of traffic. Of course, this is just a general guideline - there are always exceptions. Some people have been approved with as little as 10 views per day. So it really depends on a number of factors, including the quality of your content and the niche that you're in.