Big Digits Tape Calculator

I deleted the calculator on my phone years ago and loved this app instead. I can’t find any options to go back to a normal calculator. Whats happening here?

I got this app several years ago because I have a vision impairment, and need… well, BIG DIGITS. It used to be perfect - big easy to read buttons, big numbers in the calculation window. Now the buttons have small spindly numbers, and there are small numbers on the tape. This app is now completely worthless to me. The name should be changed. There are no more big digits.

What happened to the Big Digits? The numbers are now smaller than the calculator that came on the phone. How can I get the original app, with large numbers, back?