Check input text to correct decimal point?

Hey there,

I'm doing a chemistry animation where students are going to have to input text into text boxes and have those calculations checked when clicking a check button, like below...

How would I go about in edge getting it to check the 1st top left text box (which already has the answer) to that correct decimal point?

And is there a way I can use the text tool to visually place a input text box on the stage?

Thanks in advance.