How does research about virtual manipulatives support culturally responsive teaching in elementary math classes?

In one page, please:

define cultural responsive teaching and/or culturally responsive pedagogy
explain why culturally responsive teaching is needed in a math class
explain how research about the use of virtual manipulatives in mathematics is being culturally responsive

Please note that the focus should be elementary mathematics and it is strongly encouraged that the authors listed below are quoted.

Gay, G. (2000). Culturally responsive teaching: Theory, research, and practice. New York: Teachers College Press.

Ladson-Billings, G. (1994). The dreamkeepers: Successful teaching for African-American students. San Francisco: Jossey-Bass.

Ladson-Billings, G. (1995). Making mathematics meaningful in multicultural contexts. In W. G. Secada, E. Fennema & L. Byrd (Eds.), New directions for equity in mathematics education (pp. 126-145). Cambridge, UK: Cambridge University.

Ladson-Billings, G. (1997). It doesnt add up: African American students mathematics achievement. Journal for Research in Mathematics Education, 67, 255-267.

National Council of Teachers of Mathematics. (2000). Principles and standards for school mathematics. Reston, VA: Author.

Tate, W. F. (1995). Returning to the root: A culturally relevant approach to mathematics pedagogy. Theory into Practice, 34(3), 166-173.

Tate, W. F. (2005). Race, retrenchment, and the reform of school mathematics. In E. Gustein & B. Peterson (Eds.), Rethinking mathematics: Teaching for social justice by the numbers (pp. 31-40). Milwaukee, WI: Rethinking Schools Publication.