Răspuns: ex 3)
279 + 399 = 279 + 400 -1 = 679-1 =678
↓ ∨
400-1 679
545 + 198 = 545 +200-2 =745-2 = 743
↓ ∨
200-2 745
ex.4)
217 + 136
=
224 + 129
-----------------------------
315+428
=
684 + 59
-------------------------
340+ 605
=
800+145
------------------------
305+ 585
=
243+35
------------------------
150+400
=
85+200+265
-------------------------------
867+150
=
216+389+412
-----------------------
