I agree with the article that it might be misleading to measure the rubble against US Dollar or Euro as not as much trade is done in those currencies in Russia currently. That said, if you measure the rubble against the ruppie or yuan instead, for example, the rubble has also weakened quite a bit. Weird that the article doesn't do that comparison... Strange...
If someone ends with "Do the math" instead of providing the math in the very post you know they are full of shit.