Răspuns:
7.
a)497 358+23 978=521 336
b)23 978+497 358=521 336
c)23 978+497 358=521 336
d)497 358+23 978=521 336
e)23 978+497 358=521 336
f)497 358+23 978=521 336
497 358-23 978=473 380
