Large numbers in English and Slovak. Up until fairly recently British English and Slovak usages were in agreement that a million was ten to the power of six (106), a milliard was ten to the power of nine (109), and a billion was ten to the power of twelve (1012).
This is called the “long scale” definition. American English usage was in agreement with the French, in that a million is (106), a billion is (109) and a trillion is (1012), which is based on the “short scale” definition. By the 1970s, however, the economic and financial links between the UK and USA were strong enough to make the UK Parliament decide in 1974 to harmonize the numbers, so that a billion would mean a thousand million in Britain as well. So a billion in English (AmE and BrE) now means miliarda in Slovak, and the Slovak bilión is now a trillion in English. Nobody is sure how big a squillion or a gazillion are, but we might soon have to learn.