The operation + cannot accept the arguments. [ " / Q"] , [1]

Please can someone help me with this problem. I am new to app inventor and need help urgently. Will be ever so grateful attached are my blocks.

checkuser ganswe Uploading: gques.PNG...gques


Perhaps this image will give you some ideas.

Somewhere a value of /Q is being added to by 1. You cannot add a number to an expression..

Here are some resources to help you learn to use the AI2 tools. A very good way to learn App Inventor is to read the free Inventor's Manual here in the AI2 free online eBook ... the links are at the bottom of the Web page. The book 'teaches' users how to program with AI2 blocks.

There is a free programming course here and the aia files for the projects in the book are here:

How to do a lot of basic things with App Inventor are described here: .

Also look here and here for more tutorials.

Learn about components
and visit the Library Help>Library on the MENU

Thank you for your reply, but it still seems to not work.

Did you change anything? What?

Apps of this type are impossible to debug by inspecting only the code Blocks. Only you have the code and can test it. Use the MIT debugging advice Live Development, Testing and Debugging

and Enis's comments about the built-in debgger MIT App Inventor 2 Tips – TWO DOG APPS

Put all your blocks here. Variables too. Do not screenshot images, there is a system for taking block images in the inventor app. Click with the right mouse button on an empty canvas, and click save blocks as image.

Export your .aia file and upload it here.

1 Like

math.aia (11.1 KB)

This is the attached aia file. Will be grateful if you can check it over.

I have attached an aia file below if you can look at it.

1 Like

See also here (especially point 4):

1 Like

Thank you so much for your help. I cannot express my gratitude in words.

I now have another problem:
Attempt to get item number 0, of the list [1, -12, 10, 16]. The minimum valid item number is 1.
Note: You will not see another error reported for 5 seconds.

Show the corresponding blocks.


... in hight qualitiy, see point 3 in my quide.


Thank you very much for all your help so far, i am extremely grateful. One last problem that i am currently facing is that one of my button are appearing as blank. Please see attached.

please can i have some guidance.

math (1).aia (11.1 KB)