To perform this trick, you need to use any book fewer than 300 pages. Before being able to perform the trick, you need to set up the book by clicking on “Trick Settings” button. You must fill the input fields with the first and the last words of each page of the book. To begin the trick, you click on “Launch Trick” button. You lend your smartphone to a spectator performing the following steps on the calculator: multiply a random 3-digit number by another random 3-digit number then divide the new number by a random 4-digit number. You get back your smartphone and show to the audience the final result of the calculation. Then you quietly press your finger on the multiply button to reveal the stored keywords of the corresponding page. The spectator flips the pages to the corresponding integer result number. You tell the spectator to concentrate on this random page then you reveal few words at the top and the bottom on this page. To repeat the trick, you press on the “C” button. You exit from the calculator by holding a long press on any button after clicking first on the “C” button.