Question: what is the difference between grades and years in school?
Answer: In US, mandatory school age is from 5 to 18 years old, where elementary schools (K-5th grade) from the age of 5, middle schools (6th to 8th grade) from 11 and high school (9th to 12th grade) from the age of 14. In America, we say students are in 7th Grade while British students of the same age are in Year 8.