Sum up all value in column x when column y = specified value


Example:

Id number value
123 1
123 4
123 1
123 2
789 3
789 3
789 4

I am trying to get one unique ID number with sum of its value and have that
returned on to a different wooksheet. For example:

Id Number Value
123 8
789 10

The worksheet that contains these data has hundreds of ID and I am trying to
write a vba code that does this function; however, I have no idea where to
start.

Thank you