Editing Fixed-point arithmetic (section)

===Addition and subtraction===
To add or subtract two values with the same implicit scaling factor, it is sufficient to add or subtract the underlying integers; the result will have their common implicit scaling factor and can thus be stored in the same program variables as the operands.  These operations yield the exact mathematical result, as long as no [[arithmetic overflow|overflow]] occurs—that is, as long as the resulting integer can be stored in the receiving program [[variable (computing)|variable]]. If the operands have different scaling factors, then they must be converted to a common scaling factor before the operation.