Depends how you are making it but the text should relate to the block in some way. You are using ball on collision with block set text? You can put the variables for hp on one of the objects, i prefer block, and have the block and text in a container so they relate to each other.
I am using Block on collision with ball, subtract 1 from an instance variable and set the text to that variable. I will read up on the use of containers.