The wrong formula with (90% : 90%) + (90% - 90%)

[ChinhQT]

Describe the bug
The formula was wrong with (90% : 90%) + (90% - 90%)
The app's result is = 0,09
But other app, the expected result is = 1,09

To Reproduce
Steps to reproduce the behavior:

1. Go to the application
2. Click on the expression (90% : 90%) + ( 90% - 90% )
3. Check the result and see error

Expected behavior
The expected result is = 1,09

[Wjxfi]

this app has true percentages. This covers some functionality