a) 3 x 10² + 4 x 10¹ + 5 x 1 = 3 x 100 + 40 + 5 = 345
b) 7 x 10² + 1 x 10¹ + 6 x 1 = 7 x 100 + 10 + 6 = 716
c) 4 x 10⁴ + 3 x 10³ + 0 x 10² + 1 x 10¹ + 7 x 1 = 43 017
= 4 x 10 000 + 3 x 1 000 + 0 + 10 + 7 =
= 40 000 + 3 000 + 10 + 7 =
= 43 017
d)
a x 10⁵ + 0 x 10⁴ + 0 x 10³ + 0 x 10² + a x 10¹ + a x 1 =
= a x 100 000 + 0 + 0 + 0 + a x 10 + a =
= a00 0aa; unde a ≠ 0; a = 1; 2; 3; 4; 5; 6; 7; 8; 9
⇒ 100 011 , 200 022; 300 033; 400 044; 500 055; 600 066;
700 077; 800 088; 900 099 → numerele naturale
