Test development efforts for constructing 12 items to measure achievement of each of 30 selected mathematics concepts are described. The topics covered are sets, division and expressing relationships. Item and total score statistics for data collected on 196 girls who had just completed the fifth grade during early summer of 1970 and 195 boys who had just begun the sixth grade during the fall of 1970 are presented and discussed. For related documents, see SE 015 462 and SE 015 469. (Author/DT)