Răspuns :
500 + 50 = 5 * 100 + 5*10
600 + 20 = 6*100 + 2 * 10
200 + 70 = 2 * 100 + 7 * 10
800 + 60 = 8 * 100 + 6 *10
300 + 50 = 3 * 100 + 5 * 10
600 + 20 = 6*100 + 2 * 10
200 + 70 = 2 * 100 + 7 * 10
800 + 60 = 8 * 100 + 6 *10
300 + 50 = 3 * 100 + 5 * 10
500+50= 5x100+5x10=550
600+20=6x100+2x10=620
200+70=2x100+7x10=270
800+60=8x100+6x10=860
300+50=3x100+5x10=350
600+20=6x100+2x10=620
200+70=2x100+7x10=270
800+60=8x100+6x10=860
300+50=3x100+5x10=350