Pairs to Billions (short Scale) (pr to B)

1 pair equals 2×10⁻⁹ billions (short scale) exactly.

1 pair = 2×10⁻⁹ billions (short scale)

How to convert pairs to billions (short scale)

To convert pairs to billions (short scale), multiply the number of pairs by 2×10⁻⁹. This factor is exact. To go the other way, multiply billions (short scale) by 500,000,000.

billions (short scale) = pairs × 2×10⁻⁹

Example: 10 pairs = 2×10⁻⁸ billions (short scale).

Large-number names differ around the world: this site uses the short scale (billion = 10⁹) by default, and lists the long-scale billion separately.

About these units

Pair (pr)

General & non-SICurrent unit

Two items.

Pair comes from Old French paire, which grew out of Latin paria, the neuter plural of par, meaning equal. German Paar and Dutch paar are relatives of the same word. The core idea is two matching things taken together, as in a pair of shoes or gloves.

English also uses pair for single objects built from two connected parts. Scissors, spectacles, trousers, and jeans are plural-only nouns, so a counting word is needed: you say a pair of scissors or several pairs of jeans. That makes the unit slightly slippery. Six pairs of socks is 12 socks, but six pairs of scissors is only six objects. The word has other senses too, such as two people in a relationship or two cards of equal rank in poker, but as a quantity of loose items it is always two.

1 pair = 2 pieces (exactly).

Sources: Wiktionary: pair

Billion (short Scale) (B)

General & non-SICurrent unit

One thousand million (10⁹). The meaning used in the US, UK and most English-speaking countries today.

For decades British and American speakers meant different things by billion. The short-scale sense, a thousand million, took hold in the United States in the 19th century, while Britain kept the older meaning of a million million. From the 1950s the short scale spread through British technical writing and journalism, and Winston Churchill had remarked in 1941 that for practical financial purposes a billion was a thousand millions.

The official break came on December 20, 1974. Asked in Parliament whether ministers would be required to use the traditional British meaning, Prime Minister Harold Wilson answered no, explaining that billion was now used internationally for 1,000 million and that using it any other way would cause confusion. He conceded it could still be read as a million million and asked colleagues to avoid ambiguity. Today a billion is 10⁹, matching the SI prefix giga, and the UN projected that world population would reach 8 billion on November 15, 2022.

1 billion (short scale) = 1,000,000,000 pieces (exactly).

Sources: Hansard, 20 Dec 1974: Billion (Definition), written answer; Wikipedia: Billion; United Nations: Day of Eight Billion

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