Javascript Calculator failed to pass test #9, #12, #13 and #14

Good day!

This is my version of Javascript Calculator:

I can not understand why it can’t pass test #9, #12, #13 and #14. When I make calculations by myself, answer is same like in the test, but when run it througth test, it is failed.

Please give me some hint where I missed problem.

Thank you!

it pass perfecly (16/16 Passed) when I tested the codepen that you provided it

try: test it with other bowser or in local terminal.

Thank you for your comment!
Now it can pass because with a help of people from the stackoverflow website, I solved this problem.
The problem was that calculator had wrong id’s for ‘+’ and ‘-’ buttons The tests are using the button id to press it, not its text.