Time structure refers to the ratio of time spent moving during visible segments and occluded segments in position prediction motion (PM) tasks. Recent research has found that an equal time structure can improve performance in position prediction motion tasks. However, there is no research to explore the influence of time structure on the number PM task. In three behavioural experiments, this study explored whether an equal time structure improved number prediction motion performance, as it did in position tasks. The results demonstrated that an equal time structure could improve participant performance in the number prediction motion task (Experiment 1). However, equal time structures did not improve task performance when the numbers before the transition number were presented regularly one by one (Experiment 2). Experiment 3 showed that participants could actively take advantage of equal time information when the numbers before the transition number were presented irregularly. These findings demonstrated that when the number sequence was not presented in order, people could use the time structure heuristics to estimate completion time estimates (CTEs). People could sub-vocally count through mental number space when the number sequence was presented in order.