how much wool for a sleeve?

i bought some wool from tiger a while ago, i also found a pattern i wanted to use it on but the pattern must be wrong. it said i needed 10 x 25g balls. mine are 50g and have 11so tho ught would be fine. tension square on a 6mm needle was tiny bit bigger so went ahead. but have only managed about 4 inches of knitting and have almost finished 2nd ball. i have scoured all shops, written to head office and even gone on a site that lists people with left over tiger wool but none have any of it left. its a lovely multicoloured yarn and really want to knit it but jumper is 16 1/2 inches just to the shape shoulders bit so am definitely going to run out. it is a weird wool in that its chunky in some bits and more like a dk in others. i might have enough for back and some of front so was going to get some purple wool to do whatever is left of neck that needs doing and sleeves. looked at yarn on site that says super chunky knits but that knits to a 10mm needle whereas their normal chunky knits to a 6.5mm needle so think i need the latter, but how much do i need of the chunky to do both sleeves allowing bit extra to do bit of front. it comes in 100g balls but dont want to run out again. so what i am asking is that given the details above how many of these 100g chunky balls of wool will i need. hope this is not too confusing am still only a self taught beginner, thanks for any advice given

You really want to consider yards/meters rather than weight in grams. What weight yarn (in the sense of chunky, worsted, dk) does the pattern call for and how many yards or meters? What is the name of the yarn you have?
In general, figure 1/3 of the yarn for front, 1/3 for back and 1/3 for sleeves.
Can you give us a link to the pattern or a pattern name?

I agree with salmonmac. Grams isn’t a useful measure anymore because you can have a 100 grams of laceweight or a 100 grams of worsted and while they are the same weight they are not the same thing and they will knit up differently.

What pattern are you making? Name and link if possible? Also what is the name of the yarn you’re using and the name of the yarn suggested.