找出缺失的数字，然后将答案放入提供的框中。
找出缺失的数字，然后将答案放入提供的框中。更多加减练习，请尝试< a href = " https://www . education . com/worksheet/article/Missing-Digits-Addition/">Missing Digits:Addition 和< a href = " https://www . education . com/worksheet/article/Missing-Digits-减法/" > Missing Digits:减法。
