San Francisco - Questions about BART tickets

My family (2 adults and 2 children) will be spending a long weekend in downtown San Francisco without a car - dropping off the car at the Avis in Union Square on the Friday. On Monday we will need to get to SFO and I was looking at buying BART tickets. It looks like the 2 adults will cost $8.10 each and I noticed that children cost $3.05 each but it looks like you cannot buy these single value tickets (is this the case?). Then I noticed that you can buy a $24 pass for children for $9 - could both the children use this ticket? I know in NYC you can have several people using a single ticket but I can't see anything about this on the BART site.

Any help is appreciated.

B.

Each person must have his/her own ticket. You cannot use the same ticket for 2 people, children included.

For this group, you might as well take a taxi. The price would be almost the same.

For this group, you might as well take a taxi. The price would be almost the same.


A taxi will run about $30-$35 plus tip if its after July 1.