Not exactly. In base 1 they don't have to be in a row because the order doesn't matter. For example, 16 could be 16 ones in a row, or 4 rows of 4 ones, 2 rows of 8, or 16 in a circle, an X, or a completely disorderly bunch.

123 + 456 = 123456 Or translated to decimal 3 + 3 = 6