![](http://2.bp.blogspot.com/_TKlpx267e90/TCESJfMxKOI/AAAAAAAAGII/3KskVeNf-uo/s400/beforeafterpenny.jpg)
We tested 4 different methods as outlined on e.how.
1. Ketchup
2. Baking soda and water paste with toothbrush
3. Lemon juice and salt [or vinegar and salt]
4. An eraser
![](http://2.bp.blogspot.com/_TKlpx267e90/TCESV8xjjSI/AAAAAAAAGIY/5uE3b0h_sBk/s400/IMG_6312_2.jpg)
![](http://2.bp.blogspot.com/_TKlpx267e90/TCESWBqWJSI/AAAAAAAAGIg/ErxHBvQjNrE/s400/IMG_6311_2.jpg)
We tried a penny with each method and then tried different combinations. The lemon juice and ketchup both had the most dramatic results. And it was fun to put a penny in the lemon juice right after the baking soda for extra bubbly results.
![](http://2.bp.blogspot.com/_TKlpx267e90/TCESVi1YFmI/AAAAAAAAGIQ/drBT6Fpeps8/s400/IMG_6316_2.jpg)
The eraser was our least favourite.
![](http://4.bp.blogspot.com/_TKlpx267e90/TCESWftfxAI/AAAAAAAAGIo/WAVv4nDVMoE/s400/IMG_6309_2.jpg)