4 5/12 - 3 7/18 = 53/12 - 61/18 = (159 - 122) / 36 = 37/36 37/36 : 9 25/100 =37/36 * 100/925 = 3700 / 33300 = 37/333 37/333 + 5/6 = (74 + 555) / 666 = 629/666 4/10+ 1/8 = (20 + 5) / 40 = 25/40 = 5/8 5/8 + 75/100 = (250 + 300) / 400 = 550/400 =55/40 55/40 * 2/3 = 110/120 629/666 :110/120 = 629/666 * 120/110 = 8280/ 73260 = 828/7326 =138/1221