The Influence of Playing with Number Blocks on the Increase in Counting Ability in Class 4 Mental Retardation Children in SDLB/C Aditama Surabaya

Background: The number block is a media that Montessori created in 1909. This made of wooden square and consists 10 blocks with red blue colors. Each segment represents the sum 1 block. According to Fridani Kompas Daily (2010), game itself has several advantages, including children can recognize mathematical concepts because by playing blocks, get know more - less, same not same, numbers science. Such as calculating, classification, gravity, stabilization.Objective: To determine effect on increasing numeracy skills mentally disabled childrenMethod: research design was pre-experimental one group pre-test post-test approachResults: Before being given intervention play numeric most ten respondents (59%) had level (analyzing symbols, addition, subtraction) mental retardation, which low category. Mental good category for eight (47%), five (29%) are included category.Conclusion: There an retardation before after blocks.