Welcome to the Ranch
I added
code tags to your post: always use them. Doesn't it look better
I shall move the post to our GUIs forum
Unfortunately I can see some really poor design.
You should probably get rid of addActionListener(this). One Listener per button, or if you use Java8 you can use a λ instead. The block of ifs is dreadful for maintenance. You have the numbers as fields of those buttons and you are not using those fields.
Using numbers to represent the actions you want to do is also pretty bad, I am afraid. You can simply use [i/] × 
y or similar. Or you can call a different method from each listener. But that should be in some different classes.
I can't see where you are changing sizes.