Base Ten Blocks provide a spatial model of our base ten number system. The smallest blocks—cubes that measure 1 cm on a side—are called units. The long, narrow blocks that measure 1 cm by 1 cm by 10 cm are called rods. The flat, square blocks that measure 1 cm by 10 cm by 10 cm are called flats. The largest blocks available that measure 10 cm on a side, are called cubes. When working with base ten place value experiences, we commonly use the unit to represent ones, the rod to represent tens, the flat to represent hundreds, and the cube to represent thousands. Providing names based on the shape rather than on the value allows for the pieces to be renamed when necessary. For example, when studying decimals, a class can use the flat to represent a unit and establish the value of the other pieces from there.
The size relationships among the blocks make them ideal for the investigation of number concepts. Initially students should explore independently with Base Ten Blocks before engaging in structured activities. As they move the blocks around to create designs and build structures, they may be able to discover on their own that it takes 10 of a smaller block to make one of the next larger blocks. Students' designs and structures also lead them to employ spatial visualization and to work intuitively with the geometric concepts of shape, perimeter, area, and volume.
Base Ten Blocks are especially useful in providing students with ways to physically represent the concepts of place value and addition, subtraction, multiplication, and division of whole numbers. By building number combinations with Base Ten Blocks, students ease into the concept of regrouping, or trading, and can see the logical development of each operation. The blocks provide a visual foundation and understanding of the algorithms students use when doing paper-and-pencil computation. Older students can transfer their understanding of whole numbers and whole-number operations to an understanding of decimals and decimal operations.