a) 538 = 5.100 + 3.10 + 8.1 = 5 . 10 2 + 3 . 10 1 + 8 . 10 0 .
b) 8609 = 8.1000 + 6.100 + 9.1 = 8 . 10 3 + 6 . 10 2 + 9 . 10 0 .
c) a b c = a.100 + b.100 + c.l = a . 10 2 + b . 10 1 + c . 10 0
d) a b c d = a.1000 + b.100 + c.10 + d = a . 10 3 + b . 10 2 + c . 10 1 + d . 10 0