748 – 9 = 739;
512 – 7 = 505;
379742 – 5 = 379737;
4893 + 8 = 4901;
567859 – 8 + 7 = 567851 + 7 = 567858;
67457 – 9 + 5 = 67448 + 5 = 67453.