Underscore visibility qurey

Good day

I am a new user to Python and have downloaded Idle (Python version: 3.4.3; Tk Version: 8.5.9; IDLE version: 3.4.3). I am using the book "Python for kids" as a starter and have noticed that when I try to use the underscore (_) in the Python shell the underscore is not visible. Is there any way to rectify this?

I have copied the two lines of code from the Python shell window below and the underscore is definitely there - just not visible!

>>> number_of_coins=200
>>> print(number_of_coins)

Regards

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