The understanding one needs to work with percentages is:
1/100 = 1% = 0.01
Also
6/100 = 6% = 0.06
also
25/100=1/4=0.25=25%
To find a spesific share of a total, we can multiply the perectage with the total, like this: Total * 6% or in a way easier to work with: Total * 0.06 or (Total * 6)/100
If you have a calculator i would recommend using the decimals, as they are one of the easiest to type in - and remember once you get the hang of it.
To find the money Nina has saved, you do the following.
150*0.06=9$
Nina has saved 9 dollars.
The remaining percent she needs, is
100-6=94%
She still needs money for 94% of the bike.