Well, darling, 555 plus 321 equals 876. It's simple math, honey, nothing to lose sleep over. Go ahead and impress your friends with your newfound knowledge of addition.
321 + 321 = 642
555 + 555 = 1110
555 + 555 = 1110
555 plus 5 plus 556 is equal to 1,116
222 + 333 = 555
44 + 555 + 211 = 810
320 + 321 + 160 + 161 = 962
444+555=999
-182 + 321 = 139
55555555+555=5555611000
100+555=655
555 + 250 = 805