Ah. I see.

Your example is way too easy, however. Persimmon Leaf Sushi is not a crafting material, but a finished product.

Your question was my first major hurdle, too. I had to sit and think on a formula that would properly resolve that issue. I didn't want my spreadsheet to tell someone to make 9 batches of diluted vitriol when all they needed was 9 total. This is how I resolved it:

I assigned a "yield" to every recipe. Take this cell contents from worksheet "The Calculator" BC6

=IFERROR((ROUNDUP((VLOOKUP(BB6,$B:$J,8,FALSE)-BE6)/VLOOKUP(BB6,$B:$J,9,FALSE),0)),"")

BB6 = item
Column K (vlookup) = needed TOTAL of requested item (BB6)
BE6 = user input
Column J (Vlookup) = recipe yield

Iferror is so the spreadsheet looks pretty. It also got me in trouble, though, with that rogue column of formulas that caused circular referencing!