Home Street — pick a topic to practise metric conversions.
Build columns to an exact height — mm, cm and m.
Balance the scale exactly on target — g, kg and t.
Fill a container to an exact volume — mL, L and cm³.
Pick blocks from the Yard to build a column exactly as tall as the Target.
Pick weights from the Weight Yard to balance the scale exactly on target.
Pick blocks from the Yard to fill a container exactly to the Target.