The second school was involved in iteration 4, where 25 fifth-grade primary school students participated. Both schools had parental consent for the students involved. According to teacher inter- views, the students in both schools predominantly come from middle-low-income families. While almost all...
The following extract is from a grade 5 mathematics classroom, where the teacher asks questions of the whole class before they begin to work in small groups on the topic of decimals and fractions. The class size is 55 students. Extract 2: Elementary school, a female teacher = Miriam, ...
直角三角形斜边上的中线等于斜边的一半.反过来.如果一个三角形一边上的中线等于这边的一半,则这个三角形是直角三角形,这边所对的角就是直角.对于三角形的中位线,由于它的"唯一性",可知经过一边中点且平行于一边的直线必经过另一边的中点,这条直线被三角形所截的线段也必是一条中位线.中学生数理化(八年级数学)...