Dintre exercitiile:
1
2(a,b,d)
4(a)
6(b)
7
8
Dau coroana

1. a) 15-43-27
-28-27=-55
b) 413-395+11= 18+11=29
c)642+423-999= 1065-99=66
d) 725-696+37=29+37=66
e)2138-809+57= 1329+57=1386
f)521-99+17-47=422+17-47=439-47=392