Integer Division Operator - \

The back slash operator performs integer division.

Debug.Print 7 \ 3           '= 2  
Debug.Print 9 \ 4           '= 2  
Debug.Print 20 \ 3          '= 6  
Debug.Print 100 \ 3         '= 33  
Debug.Print 10 \ Null       '= Null  
Debug.Print Null \ 10       '= Null  

This is a great way of dividing and rounding down in one simple operation.
Before performing the division any floating-point values are converted to long integers.

The data type returned is a numeric type appropriate for the data types used

Dim myLong As Long 
myLong = 2147486647 
Debug.Print TypeName(myLong \ 1)     ' "Long"