276232:4*30-258363:7*30
276232 / 4 * 30 - 258363 / 7 * 30 = 964470 1)276232 / 4 = 69058 2)69058 * 30 = 2071740 3)258363 / 7 = 36909 4)36909 * 30 = 1107270 5)2071740 - 1107270 = 964470