they never taught me this at school

So, this evening I have been attempting to do a little homework. I am trying to learn about compound depreciation, because I need to use it in some spreadsheets at work. I'm no mathematician, and it's over 20 years since I scraped through my GCSE. But I think I have a handle on it now:

If I have £100 now, and I have 5% depreciation, after 1 year it will be worth £95. Then in year 2 it will be worth 95% of £95 (£90.25). And in year 3 it will be worth 95% of £90.25 (£85.73) and so on.

I asked my dad about it, because that's what you do. And he told me about compound interest, which is what this photo is of - my notes from our conversation.

I hope that a) I remember how this works, and b) my assumption that compound depreciation works the same way in principle as compound interest is correct!