Virtual Manipulatives - Base Ten Blocks

Base ten blocks and the concept of making and breaking tens is a big idea in second grade that I want my students to leave having confidence in understanding. I decided to research the available virtual manipulatives that address this idea.

The National Library of Virtual Manipulatives has three base blocks manipulatives I could use with my students:

• Base Blocks consists of individual "units," "longs," "flats," and "blocks" (ten of each set for base 10). They can be used to show place value for numbers and to increase understanding of addition and subtraction algorithms. Users can enter base block pieces, set the base and number of decimal places, represent numbers, exchange and group pieces and show problems.
  
• Base Blocks Addition uses the virtual base blocks providing addition exercises that demonstrate exchanging and grouping pieces. Manipulators have the option to set the base and create their own problems.
• Base Blocks Subtraction uses the virtual base blocks to model the canceling of blue blocks with red blocks. The manipulatives can be exchanged and grouped, exercises for subtraction are available as well as creating your own problem. The base may also be changed.

Houghton Mifflin Math has its own base ten block eManipulatives. This mathematical tool has a simple interface that allows users to "stamp" tens (flats) and ones (singles) onto the appropriate spot on a place value mat and an option to have the total written out and read. The virtual manipulative has a child-like aesthetic and is basic. There is an option to use a place value mat to generate one or two numbers.

Glencoe / McGraw Hill has a online working space which can be found here. There are a variety of working mats and backgrounds that can be chosen. My favorite feature of these base ten blocks is that the ones, tens or hundreds can be dragged together or clicked to be separated.

Overall, I think I prefer the National Library of Virtual Manipulatives best. I think its simple interface is straightforward. I also like that the units can be broken up when, for example, a ten stick is dragged into the ones column, and grouped into a ten when selected in the ones column. I find that the three options for use of base ten blocks is useful for the purposes I would be using the manipulatives for.