Help with indexing and small functions

[shrekan]

Hi all,
I usually relish in researching and sorting out my own problems and love the sense of satisfaction I get, however I've reached a brick wall and time is pressing.

East London Line Driver Log.xlsm

Heres the scenario:
I enter the unit number and the meters driven into Table A. I want this to then update Table B, adding itself to the appropriate unit running total.

TABLE A

TABLE B

I cannot use VLOOKUP as it stops at the first instance found.
I've been playing with the INDEX and SMALL functions and had a limited amount of success.
If you have a solution or could point me to the correct function for this task, I would be greatly thankful.

 

[Scott R]

Looks like you should use SUMIF to add all 4 instances with 378141.
=SUMIF(unit_no range, 378141, mileage range)

 

[shrekan]

Thanks for your solution, it needed the sumif function and its works.