11. Completează casetele libere: a) 31+42 = 342; * 4 + 600 = 2200; 7* 5+=100 * 1; b) 0 x 10+ 90; x 2 = 100; x 8+ 700 = X

Răspuns:
3x100+42=342
4x100x4+600=2200
7x5+65=100x1
0x10+90=90
10x8+10x2=100
700=7x100