Strings, StringBuffers, StringBuilders, Numbers, and BigNumbers - Java for COBOL Programmers - page 206

TABLE 8.5 ROUNDING OPTIONS IN JAVA AND COBOL

Mode Description COBOL Equivalent

ROUND_CEILING Round toward positive infinity.

ROUND_DOWN Round toward zero (and away from 10).

ROUND_FLOOR Round toward negative infinity.

ROUND_HALF_DOWN Round toward “nearest neighbor”

(i.e., toward 0 or 10). If both neighbors
are equidistant, round down.

ROUND_HALF_EVEN Round toward the “nearest neighbor.”

If both are equidistant, round toward
the even neighbor.*

ROUND_HALF_UP Round toward “nearest neighbor.” ROUNDED

If both are equidistant, round up.

ROUND_UNNECESSARY Asserts that the requested operation

has an exact result, and no rounding
is necessary.

ROUND_UP Rounds away from zero (toward 10).

* This mode should, in theory, round up as often as it rounds down in case of equidistant neighbors, thereby reduc-
ing one source of rounding error.

Table 8.6 shows the most common math functions involving BigDecimal s.