Become a pro at times tables! Use the water based pen to fill in your answers, then pull the tab to check to see if you are correct! Excellent pull tab book with pen geared towards a child's journey to learning multiplication! Become a pro at mathematical multiplication in no time! Use the water-based pen to fill in your solutions, then pull the tabs to check if you got it right. Want to practice some more? Just erase and start again! This board book can be used over and over again, as the pull tabs are sturdy.