10% of ten English pounds £ I, unfortunately, have serious dyscalculia and struggle with maths. This makes figuring out simple everyday maths quite difficult. I'd really appreciate the help with this. Thanks in advance.

Ten percent is one-tenth, or one in ten.  (This is equivalent to $10/100$, or $10$ per $100$, as JMoravitz pointed out above.)
So, if you have $10$ pounds, one in ten of them is $1$ pound.
Similarly, $10\%$ of $50$ pounds would also be one for every ten, or $5$ pounds.
Graphically, you can arrange the pounds in rows of $10$ and take just the first one of each row.
Fractions are a little tougher.  After you take the first one from every full row of ten, then you'll need to break up each pound into $10$ pieces, line those up into rows, and take the first piece from each row.
So for $46$ pounds:  You have $4$ full rows.  There are six left over.
So line up the $6 \times 10$ pieces into six rows of ten, and take the first piece from each row: $6$ tenths.
Then, $10\%$ of $46$ pounds is $4 \frac{6}{10} = 4.6$ pounds.
Hope that helps.
