0.1
A decade is 10 years. 2012 is one year. There are no decades in a single year. The years 2002 - 2012 represents a decade.
One decade is ten years. That means that 511 decades would be 5110 years, or 511x10. One year has 365 days, and every fourth year is a leap year, so 511 decades would be 1866427 days.
One decade = 10 years. 49 decades = 490 years. There are 52 weeks in one year: 490 x 52 = 25480 weeks in 49 decades
There are 12 decades in a 120 year period.
If one year has 12 months, then a decade would have 120. And two decades would be the double of that, so 240
12
7 decades which is 70 years
77 decades and 1 year 77.1 x 10 = 771
30 years
20
Ten decades is one century.
100 decades are in one thousand years.