To solve the problem, we need to find the total cost of the two books and then determine how many quarters Sadie needs to pay that amount.
The first book costs $2.50 and the second book costs $3.00, so the total cost is $2.50 + $3.00 = $5.50.
Next, we need to convert the total cost to quarters. A quarter is equal to $0.25, so $5.50 / $0.25 = 22 quarters.
So, Sadie will need 22 quarters to pay for her purchase