How do I detect and save keyboard entries?

Hi, I'm making a game to help some kids to learn math.

In the game some meteors comes towards you and the meteor have 2 numbers, so you have to multiply it and type the answer to destroy the meteor.

How can I identify and compare the keyboard sequence typed to the correct answer?

f.e I get the meteor 7*5 so the answer is 35, what can I do to when I type 35 on my keyboard it destroys de meteor?

Here is a basic example:

https://www.dropbox.com/s/ag679acukgwbt ... .capx?dl=0