Book It Pizza Coupons

I have set a reading goal of 2 books a week for each child.  These are their Tuesday/ Thursday homework books.  If they read all the books for the month, they will receive a free pizza coupon from Pizza Hut for the month.  Book It runs from October through March.  I will keep track of the books but if they do not return their books so they can get a new one, they may run into a problem of not reading the number of books for their goal.  If they are only 1 or 2 books away, I will try to have them read me one at school so they still get the coupon.  But if they consistently are not returning books on time and rechecking them out, they might not get the coupon for that month.  October's coupons are coming home tomorrow.  They are small, about 2 1/2 inches by 4 inches.  I will try to get the kids to put them in the clear plastic sleeve in their binders.  The coupons do expire one month from the date of issue.