Table space calculation based on tablespace and import in 11g

 Hi,

a)   Can anybody please explain how the space was calculated for the following ACCOUNTING table based on import and USERS tablespace in 11g.

1) Import information

CREATE TABLE "ACCOUNTING " ("BU_ID" NUMBER(8, 0), "TERM_NUM" NUMBER(4"

 ", 0), "ACCOUNTING_DATE" DATE )

PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 LOGGING STORAGE(INITIAL "

 "250142720 NEXT 3383296 MINEXTENTS 1 MAXEXTENTS 249 PCTINCREASE 1 FREELISTS "

 "1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT) TABLESPACE "USERS""

  2) USERS tablespace

  2) USERS tablespace

  2) USERS tablespace

SQL> select * from dba_tablespaces where tablespace_name='USERS';

  TABLESPACE_NAME                BLOCK_SIZE INITIAL_EXTENT NEXT_EXTENT MIN_EXTENTS

  TABLESPACE_NAME                BLOCK_SIZE INITIAL_EXTENT NEXT_EXTENT MIN_EXTENTS

  TABLESPACE_NAME                BLOCK_SIZE INITIAL_EXTENT NEXT_EXTENT MIN_EXTENTS