EXHIBIT 21 SIGNIFICANT SUBSIDIARIES NATIONAL COMPUTER SYSTEMS, INC. STATE OR OTHER JURISDICTION OF NAME UNDER WHICH NAME OF SUBSIDIARY INCORPORATION SUBSIDIARY DOES BUSINESS - ------------------------------ ------------- ------------------------------ NCS Assessments, Inc. Minnesota National Computer Systems, Inc. NCS Assessments Macro Educational Systems, Inc. California National Computer Systems, Inc. Education Software and Services Division of National Computer Systems, Inc. Note: No other subsidiary of National Computer Systems, Inc. meets the conditions to be deemed a significant subsidiary.