Input and Show self generated Keyboard Entries in a TextBox or a Label

I made a Keyboard on a Canvas and want to input in a TextBox the numbers wich is touched. Every entered number must be there in the textbox. But in my example deletes every touch the previous number and writes the new number.

simply:

image

join the value of your "number" touched to the existing value in the textbox
(here I used a button instead of a canvas touch event)

That works fine. Thanks. And now, how to delete the entered numbers, one by one? Not the entire entry.

Use the length and segment blocks in the Text palette to remove the last character of your textbox text.

Before you ask: