To convert x to a double-precision number.
x must be a numeric expression.
10 A=454.67 20 PRINT A; CDBL(A) RUN 454.67 454.6700134277344
Prints a double-precision version of the single-precision value stored in the variable named A.
The last 11 numbers in the double-precision number have no meaning in this example, since A was previously defined to only two-decimal place accuracy.