# 12 plus 4 in mod 10

• April 9th 2011, 02:02 PM
MSUMathStdnt
12 plus 4 in mod 10
What is 12 plus 4 in mod 10? Shouldn't that be 12+4=16-10=6?
Or even 12-10=2, 2+4=6?

My book says "Be careful, the answer is not 6".
• April 9th 2011, 03:00 PM
Chris L T521
Quote:

Originally Posted by MSUMathStdnt
What is 12 plus 4 in mod 10? Shouldn't that be 12+4=16-10=6?
Or even 12-10=2, 2+4=6?

My book says "Be careful, the answer is not 6".

Maybe they want you to say it this way?

$12+4\pmod{10}\equiv 16\pmod{10}\equiv 6\pmod{10}$