These are rectangular pieces that are all the same height, but with lengths
determined by the fractional part they represent.
When all the fractional pieces of each color are put together, they form bars, or rows,
that are the same total length.
Tiles are marked with the fractions they represent.
By placing strings of tiles beneath each other, it is easy to determine equivalence.
The fraction bars may also be used as weights.
The length of each bar is in direct proportion to the weight thereof.