638 + 577 = 1215
253 + 638 = 891
638 + 574 + 496 + 584 = 2,292
8976 + 638 - 234 = 9380
985
3084
635 + 3 = 638
638.
line them up above eachother 645 577 5+7=12 40+70=110 600+500=1100 add them up and you have 1222
79.75
1 x 577, 577 x 1
What does 638 mean
577 x -1 -577 x 1