### 9.1.2 Numeric Literals

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 Number literals include exact-value (integer and [`DECIMAL`](fixed-point-types.html)) literals and approximate-value (floating-point) literals.

 Integers are represented as a sequence of digits. Numbers may include `.` as a decimal separator. Numbers may be preceded by `-` or `+` to indicate a negative or positive value, respectively. Numbers represented in scientific notation with a mantissa and exponent are approximate-value numbers.

 Exact-value numeric literals have an integer part or fractional part, or both. They may be signed. Examples: `1`, `.2`, `3.4`, `-5`, `-6.78`, `+9.10`.

 Approximate-value numeric literals are represented in scientific notation with a mantissa and exponent. Either or both parts may be signed. Examples: `1.2E3`, `1.2E-3`, `-1.2E3`, `-1.2E-3`.

 Two numbers that look similar may be treated differently. For example, `2.34` is an exact-value (fixed-point) number, whereas `2.34E0` is an approximate-value (floating-point) number.

 The [`DECIMAL`](fixed-point-types.html) data type is a fixed-point type and calculations are exact. In MySQL, the [`DECIMAL`](fixed-point-types.html) type has several synonyms: [`NUMERIC`](fixed-point-types.html), [`DEC`](fixed-point-types.html), [`FIXED`](fixed-point-types.html). The integer types also are exact-value types. For more information about exact-value calculations, see [Section 12.25, “Precision Math”](precision-math.html).

 The [`FLOAT`](floating-point-types.html) and [`DOUBLE`](floating-point-types.html) data types are floating-point types and calculations are approximate. In MySQL, types that are synonymous with [`FLOAT`](floating-point-types.html) or [`DOUBLE`](floating-point-types.html) are [`DOUBLE PRECISION`](floating-point-types.html) and [`REAL`](floating-point-types.html).

 An integer may be used in floating-point context; it is interpreted as the equivalent floating-point number.

