How much formula if BF-ing morning and evening.. help please!

[BettyOoh]

DD is going to nursery next week full-time and I've decided to send her with formula, but as she's been EBF until now I haven't got a clue about how much she needs. She's 9 months.
She'll get a big BF in the morning and again in the evening, so she only really needs milk at lunchtime. How much formula is the equivalent to a normal BF? Also she currently only drinks out of a beaker when she has water, she been refusing bottles for ages now. Is it alright for them to drink formula milk out of beakers? I went to our trial nursery session yesterday and babies alot older than DD were still drinking out of bottles. Is there a reason they aren't using beakers?

Sorry I sound a bit dim, any help appreciated!

How many breastfeeds does she normally have in that time?

I'd probably get them to give her formula in a cup at snacktime, morning and afternoon, but that's when my ds tends to breastfeed.

Older children probably still have bottles as they've always had bottles and it's hard to get them to give them up. At 9 months though there's no need to give a bottle - if you do you'll just have to get her off them later anyway.