A unit block is a type of standardized wooden toy block

Toy block

Toy blocks , are wooden, plastic or foam pieces of various shapes and colors that are used as building toys...

 for children. Known also as standard unit blocks or kindergarten blocks, these building blocks are common in preschools and some kindergarten

Kindergarten

A kindergarten is a preschool educational institution for children. The term was created by Friedrich Fröbel for the play and activity institute that he created in 1837 in Bad Blankenburg as a social experience for children for their transition from home to school...

 classrooms in the United States.

Sizes

A unit block is 5.5 inches long, 2.75 inches wide, and 1.375 inches thick. Larger pieces include the double (11 inches long) and quadruple (22 inches long) sizes. Smaller sizes are made in various fraction

Fraction

In common usage a fraction is any part of a unit.Fraction may also mean:*Fraction , one of more equal parts of something, eg...

s of the standard unit.

History

The unit block principle was developed by educator Caroline Pratt in the early 1900s. Pratt founded the City and Country School in 1914 in New York City.

Wood

Unit blocks vary in price according to the wood used and the manufacturer. Maple

Maple

Acer is a genus of trees or shrubs commonly known as maple.Maples are variously classified in a family of their own, the Aceraceae, or together with the Hippocastanaceae included in the family Sapindaceae. Modern classifications, including the Angiosperm Phylogeny Group system, favour inclusion in...

 blocks (the original wood put forth by Pratt) are more expensive than birch

Birch

Birch is a tree or shrub of the genus Betula , in the family Betulaceae, closely related to the beech/oak family, Fagaceae. The Betula genus contains 30–60 known taxa...

 or beech

Beech

Beech is a genus of ten species of deciduous trees in the family Fagaceae, native to temperate Europe, Asia and North America.-Habit:...

, which in turn are more expensive than rubberwood

Rubberwood

Rubberwood is wood from the Pará rubber tree . Rubberwood has been produced on a small scale, but has become much more common. There are extensive plantations with these trees in southeast Asia; the earlier practice was to just burn the tree at the end of its latex-producing cycle, due to the poor...

.