DEX-COOL ELC ANTIFREEZE CONCENTRATE ,1 Gallon

1 (one, unit, unity) is a number, numeral, and glyph. 1 is the first and smallest positive integer of the infinite sequence of natural numbers. This fundamental property has led to its unique uses in other fields, ranging from science to sports, where it commonly denotes the first, leading, or top thing in a group. 1 is the unit of counting or measurement, a determiner for singular nouns, and a gender-neutral pronoun. Historically, the representation of 1 evolved from ancient Sumerian and Babylonian symbols to the modern Arabic numeral.

In mathematics, 1 is the multiplicative identity, meaning that any number multiplied by 1 equals the same number. 1 is by convention not considered a prime number. In digital technology, 1 represents the "on" state in binary code, the foundation of computing. Philosophically, 1 symbolizes the ultimate reality or source of existence in various traditions.

The gallon is a unit of volume in British imperial units and United States customary units. Three different versions are in current use:

• the imperial gallon (imp gal), defined as 4.54609 litres, which is or was used in the United Kingdom, Ireland, Canada, Australia, New Zealand, and some Caribbean countries;
• the US gallon (US gal), defined as 231 cubic inches (exactly 3.785411784 L), which is used in the United States and some Latin American and Caribbean countries; and
• the US dry gallon ("usdrygal"), defined as 1⁄8 US bushel (exactly 4.40488377086 L).

There are two pints in a quart and four quarts in a gallon. Different sizes of pints account for the different sizes of the imperial and US gallons.

The IEEE standard symbol for both US (liquid) and imperial gallon is gal, not to be confused with the gal (symbol: Gal), a CGS unit of acceleration.