Abstract: Elastic cord interconnected blocks in which each block contains a plurality of deep slots cut to a centrally positioned interior washer-like connecting element having a hole coaxial that can freely pass the elastic cord. The element hole is coaxial with an axial hole formed in the block by the spacing of adjacent block segments, the segment having a spacing for passing a stretched elastic cord and for locking the cord in its relaxed state. Unusual shapes can be formed with several interconnected blocks.