The operation * cannot accept the arguments: , [1014.77833], ["0,00981"] Note: You will not see another error reported for 5 seconds.

Hello everybody,

I was presented with the problem in question
it is a simple screen which only has to do some mathematical operations.
the numbers contained in the "TOT1" and "TOT2" textboxes are integers while the number contained in the "Cost" textbox is a number with a comma (0.00981) pre-inserted in the textbox because it is a constant number.

i can't solve the problem.
Please help.
Thanks a lot.

error

AppInventor takes the period "." In numbers, not a comma ",". You can use the "replace" block from the text block drawer to replace a comma with a period or just use a period.