456
456 plus what equals 1242.\
456 x 65 = 29640 and 465 x 56 = 26040 so 456 x 65 is greater.
25,536
456 plus 100 is equal to 556
123 + 456 + 7890 = 8469
898 + 456 = 1354
777568 + 456 = 778024
789 + 456 = 1245
456 + 312 = 768
66 + 456 = 522
4002 + 456 = 4458