Answer:
You can do the amount, divided by the percentage, which would get you a answer.
For example:
So, say the question said I now have 40% left of what I did when I had all of my money, and I have £180, you would do 40 divided by 10, which is 4, then 180 x 4, which would give you a subtotal of £720.
Tell me if you need more help in the comments!
Hope this helps! Xo