I have a bunch of bulk mRNA sequencing pulled off of the TCGA.  Feature names appear to be Ensembl gene IDs with a suffix.  Here is an example:

>  [995] "ENSG00000236246.1"  "ENSG00000281088.1" 
 [997] "ENSG00000254526.1"  "ENSG00000223575.2" 
 [999] "ENSG00000201444.1"  "ENSG00000232573.1" 

I am taking the intersection between these features and a set of Entrez Gene IDs.  In order to do this I am using the biomaRt package to generate a mapping between Ensembl gene IDs and Entrez gene IDs.  However, the only Entrez gene IDs I can find lack the suffixes.  Here is the head of the table that maps Entrez genes to Ensemble genes:

      entrezgene ensembl_gene_id
    1      90529 ENSG00000001460
    2       9235 ENSG00000008517
    3      10747 ENSG00000009724
    4     654364 ENSG00000011052
    5     112611 ENSG00000013392
    6      57210 ENSG00000022567

Can someone explain what the Ensembl suffixes mean and how to convert these names to Entrez?  If this can be done with biomaRt, it would be ideal.  Thanks.
The numbers are version numbers. There is information about stable ID versioning [here](http://www.ensembl.org/info/genome/stable_ids/index.html). You can just strip off the version numbers to use with biomaRt.