Hi,
I *suspect* you use a decimal data type number WITH a format set as a
general number. The data type is how the number is stored, the format is how
the number is presented to the user interface (by default, if not otherwise
explicitly formatted). It seems your storage limit for the decimal number is
reached. You have to increase it (from table design, for the implied
field(s). The Access terminology, for such field, is Data Type = Number,
and in the small section at the bottom, when the field is selected, you can
read Field Size = Decimal and Precision = ... a number between 1 and 28.
It is probably too low, try to increase it.
I started with a: I *suspect* because clearly, the problem can be
something else, given the imprecision of the context.
Hoping it may help,
Vanderghast, Access MVP