'calculate the product of x and y by accumulating the sum of x copies of y'
I'm stumped, what is it this exercise actually wants me to do? Express $x$ * $y$ as something else? I'm allowed to use an algorithm (i.e. pseudocode/math) instead of algebra, if anyone can help.
I would write an algorithm in pseudocode using a FOR loop to add $y$ to a variable (initialised as zero) $x$ times.