56/7=8
6,63/3=2,21
2 6/10 + 1/10 = 2,7
1 2/5*5/7=7/5*5/7=1
3 7/15 - 2 1/5 = 3 7/15 - 2 3/15 = 1 4/15
8/9 / 4/27 = 8/9*27/4 = 2 * 3 = 6