Press 0-9 to add, keep the same, or subtract that number from your score. If the square by the score is green, it adds, if it is yellow, your score stays the same, and if it is red, it subtracts. 0 Will only change the box color.
I made a game just like this when I first joined scratch, I stopped because I was a piece of garbage at coding, and one day, I was looking through my stuff and found the original, but it was so messed up I had to delete it, And I made This, Enjoy, and report any bugs please.