According to at least one study on average, all students, regardless of socio-economic status, lose approximately 2.6 months of grade level equivalency in mathematical computation over the summer months each year.*
Throughout the summer months we will provide fun math challenges for students on this blog. Meanwhile, here are some tips from PBS that may help. http://www.pbs.org/parents/education/math/math-tips-for-parents/summer-math/
*Cooper, H., Nye, B., Charlton, K., Lindsay, J., & Greathouse, S. (1996). The effects of summer vacation on achievement test scores: A narrative and meta-analytic review. Review of Educational Research, 66(3), 227-268.