Bar numbers in lesson 11(week 3) is a useful concept with many advantages.The bar notation which we used ,were to show repeating numbers after the decimal point like 3.3333……..=3.(3) i.e 3 point bar 3.
It was used to show the number pattern which goes on forever(infinity).
I had an impression that Bar notation can only be used if the number is the decimal number.
But now I understand that apart from being used in decimal numbers only,it has many more advantages.