Mrs. martinez is a new third grade teacher. before school started, she reviewed the entire math text and planned her approach for the year. now she moves methodically from lesson to lesson and hopes to cover all chapters by the end of the year. she knows the subject of math very well and has never had problems understanding math concepts. this week, she began teaching the lesson for week nine. she presented the new concept, and students seemed to be confused. she didn't see how they could be confused, but she repeated the same presentation. after her presentation, most of her students were unable to complete the practice problems. what is most likely the problem with mrs. martinez's lesson?