Expand foundational unit block sets with just the pieces your builders need more of. Made to align with the same mathematical dimensions as traditional unit blocks, these add-on sets are designed to be used as an enhancement to foundational sets.
These add-on pieces fit perfectly with the unit blocks we already had, which was my main worry. The dimensions line up exactly, so my daughter's towers don't wobble anymore. Finally enough pieces to go around.
My kids kept fighting over the long rectangular blocks, so this four-piece set solved that fast. They line up perfectly with the unit blocks we already had, same size and weight, no wobble when stacked. Finally enough pieces to build a decent bridge.
These add-on pieces match our existing unit blocks perfectly, so the new ones blend right in with the old set. The long rectangles were exactly what our tower builds were missing, and now there's enough to go around.