82
a minus take away a minus makes a minus
A minus plus a minus is not necessarily positive. A minus multiplied by a minus is. The reason being that the minus of a minus is a positive. It's a double negative.
Right now, it is 2013, so if you are 20 years old, you were born in 1992 or 1993. In general, if a person is 20 years old, that means that they were born in the year (this year minus 20) or (this year minus 21).
A bigger minus.
1936 - 2008 = -72
2013 minus 1958 = 55
1,993 minus 2,013 is -20.
2,013 minus 1,919 is 94.
2,013 minus 1,929 is 84.
2,013 minus 1,727 is 286.
2,013 minus 30 is 1,983.
2,013 minus 1,912 is 101.
1,956 minus 2,013 is -57.
2,013 minus 1,956 is 57.
1,942 minus 2,013 is -71.
2,013 minus 1,940 is 73.