Since 4 pounds of flour costs $2.60, we have that:

Where x is the amount of flour you get for 1 dollar.
We can rewrite the expression above as follows:

Then, we get 1.54 pounds of flour per dollar
Hi Kyliebreland!
So, If he saved $5 then we do $20 divided by $5 which gives 4 so now we split 100% into 4 pieces which gives us 25%.
Hope this helps!