Calculating numbers in text boxes without pressing a button

[Teerapat_Mueangjai]

Hello, this is my first time posting a thread.
I want to fill in the numbers in the text box and do the calculations without pressing any additional buttons.
for example
ฺBS1-BS2=int2
BS2-BS3=int3
(BS1+BS2+BS3)/3=BS4
(int2+int3)*100=int4
which i tried and it gives error When entering the test number, it freezes.
please guide me
I am not good at English Difficult to communicate, sorry.

[dora_paz (Dora)]

Set all textboxes if empty to 0 to avoid these errors. Math blocks “hates” empty textboxes

[Peter (Moderator)]

I rejected your post on the app inventor community. Only post on the community of the builder you use.

[Teerapat_Mueangjai]

Do you have an example to make the textbox have a value of 0?