11 + 2 = 13
On a 12-hour clock.
square them both and divide by 7.896504 Never
When you are doing modulo 12 calculations, for example, with hours or months.
When you are working in modulo 12 arithmetic: for example, on a clock, or the months of a year.
4 and 7
Two thousand eleven. Reserve "and" for numbers that include decimals or fractions.
When you work modulo 12; time in the 12-hour system is a good example. Or, when you introduce two cannibals to a room full of eleven people, there's usually one left over.
Two thousand and eleven.
Two Eleven was created in 2012-06.
Eleven tenths = 1.1 Therefore 1.7 + 1.1 = 2.8
211 is two hundred eleven
Two hundred eleven and two hundred eleven thousandths.