正反面分别一个框,投掷100次硬币,如出现正面一次就在正面框内记下一个黑点,用框内黑点数记录总共出现正面次数-Positive and negative, respectively, a box, throwing 100 coins, such as positive time to write down in a positive frame a black spot, a positive number of with the box black points record total