As A.fifth grade math teacher , Jenny met A.problem in teaching. She noticed .that some students entered her classroom at the second grade level, some were already at the eighth grade level, and then there were others in between. That is why Jenny began to take A.more individualizeD.teaching approach(方法) —mixed age classrooms.

Often found in non-traditional schools, mixed age classrooms were popular until the mid-19th century, when they were replaced by an age-centered, single-grade system . However, many schools turned to mixed age education again in the 1990s,arguing that it was more child-centered and suited students' development.

In mixed age classrooms , students of different ages may be in A.single class together, but they are grouped by ability in different subjects. In this way, students receive education based on what they know and what they're ready to learn next. Every chid moves forward at their own pace and

is not limited by their age. For example,9-to 11-year-olD.children who are very good at math are given the chance to learn algebra( 代 数 ) ,A.subject which is not taught until the eighth grade, when students are 12 or 13.

Studies have shown that mixed age classrooms are as effective as single-grade schooling in terms of learning achievements but better in terms of social skills . That is because students are learning how to work and play with others of different ages. Older children often take on A.leadership role and help to guide their classmates. That can be beneficial to their social skills.

However ,mixed age education also brings some challenges, especially to teachers. Teaching can be more difficult because mixed age classes tend to be larger and teachers are required to make sure that students are in the right groups . Applying such an approach to standardizeD.learning can be difficult, though not impossible.

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