This was created specifically for teachers and parents to help display visual representations of word problems.
Each letter correlates to a value and the upper and lowercase share the same width.
For example, if you want to display 1 + 9 = 10, the A represents the 1 and the lowercase a has the 1 width bracket.
The I represents the 9 bar and the lowercase 9 represents the 9 width bracket.
To show the full width, you would use the 10 which represented by the J.
A-1, B-2, C-3, etc...