The Russian ruble or rouble (Russian: рубль rublʹ, plural: рубли́ rubli; sign: ₽, руб; code: RUB) is the currency of the Russian Federation, the two partially recognised republics of Abkhazia and South Ossetia and the two unrecognised republics of Donetsk and Luhansk. The ruble is subdivided into 100 kopeks (sometimes written as kopecks or copecks; Russian: копе́йка kopeyka, plural: копе́йки kopeyki).
The ruble was the currency of the Russian Empire and of the Soviet Union (as the Soviet ruble). However, today only Russia, Belarus and Transnistria use currencies with the same name. The ruble was the world's first decimal currency: it was decimalised in 1704 when the ruble became equal to 100 kopeks.
In 1992 the Soviet ruble (code: SUR) was replaced with the Russian ruble (code: RUR) at the rate 1 SUR = 1 RUR. In 1998 preceding the financial crisis, the Russian ruble was redenominated with the new code 'RUB' and was exchanged at the rate of 1 RUB = 1,000 RUR.