C1TextBox supports a special editing mode called NumericInput mode that makes editing numeric values easier. This mode is enabled when the NumericInput property is set to True (default) and DataType is one of numeric data types (Byte, UInt16, UInt32, UInt64, SByte, Int16, Int32, Int64, Decimal, Single, Double). In the NumericInput mode, numbers are edited in a calculator-like fashion. It accepts only digits, +/- sign, and, if data type and format allow, decimal point and exponent. Other characters, such as letters, are ignored. There are also special functional keys recognized in NumericInput mode for values of type Single and Double: F9 (change sign), F2 (negative infinity), F3 (positive infinity), F4 (NaN, "not a number").

To make editing numbers even more convenient to the user, you can use the specialized C1NumericEdit control. In addition to C1TextBox functionality, it supports a drop-down calculator and up/down buttons (speed buttons) incrementing/decrementing the value by the specified Increment.