Illustrator Keeping the curve

[fcgfch]

Hello

I want to get rid of 2015 and fill the ball with black. The problem is that it's not a circle but an ellipse. How can I keep the ideal curve? When I do it with the Pen Tool it's always uneven as you can see on the second picture. Thank you in advance.

 

[Confestium]

What I did was use a vertical and horizontal ruler, use the ellipse tool and drag from the top left corner until it matches...

Highlight both, then use pathfinder and divide. Take away the bits you don't want, then highlight again and then unite.

 

[hawkeye]

Use the pen tool. Put a point on each end of the curve, then add a smooth point in the middle and adjust it to fit the curve.

 

[fcgfch]

Thanks a lot guys! You rock!