The application version 5.10 on the Apple iPhone has a bug in the load-case edit facilities that affects the numeric keyboard. At times this keyboard is not formatted correctly so that part is obscured.
When this occurs reorient the display from portrait to landscape and back again. This will fix it. Alternatively exit the load-case edit facilities back to the load-case list and then select the load-case to reenter the edit facilities again. This will also fix it.
In each session of the use of the application this problem can occur only once for each of numbers, exponents and metric prefixes.
This bug does not affect the application on the Apple iPad or any other device.