I stumble on this notion the other day.
In English/American school system, there is this notion of proper and improper fraction.
For example, 4/3 is an improper fraction because 4 is > 3. The "proper" notation should then be 1 + 1/3. It tracks with the way Americans measure everything with fractions instead of decimal notation.
The fact is I have never encounter this during my education. According to the French Wikipedia article, it's a notion that only exist in the English speaking culture, but I wonder if it's part of the curriculum in other European countries.