DiscussionThis study provided evidence of more effective self-directed learning of number sense through computer-animated activities with fifth graders in a public elementary school in southern Taiwan. The most important finding was that students in the CAEG group that received self-directed learning computer-animated number sense activities performed better on a number sense assessment than students in the PAG group who read a paper-version activities based on the same content as the computer-animated activities. This implies that children can develop number sense through self-directed learning in animation-based environments. This finding supports the statement of the NCTM (2000) that “technology can help students learn mathematics” (p. 25) and “students’ engagement with, and ownership of, abstract mathematical ideas can be fostered through technology” (p. 25). It also supports the findings of several earlier studies that technological tools can help to foster children’s mathematics learning (Chan et al., 2006; Dick, 2007; Inamdar & Kulkarni, 2007; Zbiek et al., 2007). Moreover, these findings also suggest that students in the CAEG group were more effective in their uses of number sense-based skills in solving problems than the students in the PAG group. Interestingly, we found that the students in the CAEG group who individually manipulate the animation activities applied much more uses of number sense than the students in the PAG group after the experiment. Rather, they highly decreased the incorrect responses than the students in the PAG group after the experiment. This finding strongly supports the results of an earlier study of Su et al. (2010) that web-based tools could be used to reinforce primary school children’s number sense. It also supports the finding of Yang and Tsai (2010) that student’s number sense could be improved through the technology-based environment.The students in the CAEG group performed better on number sense than students in the PAG group because students in the CAEG group have developed better conceptual understanding on number and operations under animated-based learning environment that included clearer words and pictures than the paper-version group mode.