New Content and Review
The following shows the average percentage of lesson time devoted to reviewing, introducing new content, and practicing new content in 8th grade math classes.
NOTE: Percentages may not add up to 100 because of rounding and the possibility of coding portions of lessons as "not able to make judgement about the purpose."
SOURCE: Third International Mathematics and Science Study 1999 Video Study
Vol. 22, Issue 29, Page 24