[aidenn0]

Two years after the begininng of secondary school; in general lower-secondary starts around age 11, and in the US it usually begins with Junior High which is often, but not always, 7th grade,

[doublerabbit]

In the UK ages 12-13 are typically Year 7 of secondary school.

[notreallyauser]

Year 7's regular age range is 11-12: you're 11 going into the September that the school year starts and will be 12 by the end of the following August.

[doublerabbit]

So it is, oops miscounted. Never was any good at math.