Doing the Math Right?

Are you subtracting correct when taking an age and calculating a year of birth? It might pay to doublecheck your computations so you do not create errors in your own records.

It seems like a simple thing, but a subtraction error, especially if done in your head late at night while on the computer, can easily happen.

And a year of birth calculated as 1802, when it should be 1812, might make all the difference in interpreting other records correctly.