Compute 221_3 + 122_3 in base 3.

2 answers

To compute 221_3 + 122_3 in base 3, we first align the numbers properly for addition:

221
+ 122
-------
1000

Since we are working in base 3, when the sum of any column is 3 or greater, we must carry over to the next column. In this case, the sum of the rightmost column is 3, so we carry over to the next column to get the final answer:

So, 221_3 + 122_3 = 1000_3
how about this?
221
122
----------
1120

check in base 10:
25 + 17 = 42 (3^3 + 3^2 + 2*3 + 1 = 42)