LCM for 9 and 18

The first method to find LCM for numbers 9 and 18 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:

LCM = (Number1 × Number2) ÷ GCF

GCF of numbers 9 and 18 is 9, so

LCM = (9 × 18) ÷ 9

LCM = 162 ÷ 9

LCM = 18

The second method to find LCM for numbers 9 and 18 is to list out the common multiples for both nubmers and pick the first which matching:

Multiples of 9: 9, 18, 27, 36

Multiples of 18: 18, 36, 54, 72, 90, 108, 126, 144, 162, 180, 198, 216, 234, 252, 270, 288, 306, 324, 342, 360, 378, 396, 414, 432, 450, 468, 486, 504, 522, 540, 558, 576, 594, 612, 630, 648, 666, 684, 702, 720, 738, 756, 774, 792, 810, 828, 846, 864, 882, 900, 918, 936, 954, 972, 990, 1008, 1026, 1044, 1062, 1080, 1098, 1116, 1134, 1152, 1170, 1188, 1206, 1224, 1242, 1260, 1278, 1296, 1314, 1332, 1350, 1368, 1386, 1404, 1422, 1440, 1458, 1476, 1494, 1512, 1530, 1548, 1566, 1584, 1602, 1620, 1638, 1656, 1674, 1692, 1710, 1728, 1746, 1764, 1782, 1800, 1818, 1836, 1854, 1872, 1890, 1908, 1926, 1944, 1962, 1980, 1998, 2016, 2034, 2052, 2070, 2088, 2106, 2124, 2142, 2160, 2178, 2196, 2214, 2232, 2250, 2268, 2286, 2304, 2322, 2340, 2358, 2376, 2394, 2412, 2430, 2448, 2466, 2484, 2502, 2520, 2538, 2556, 2574, 2592, 2610, 2628, 2646, 2664, 2682, 2700, 2718, 2736, 2754, 2772, 2790, 2808, 2826, 2844, 2862, 2880, 2898, 2916, 2934, 2952, 2970, 2988, 3006, 3024, 3042, 3060, 3078, 3096, 3114, 3132, 3150, 3168, 3186, 3204, 3222, 3240, 3258, 3276, 3294, 3312, 3330, 3348, 3366, 3384, 3402, 3420, 3438, 3456, 3474, 3492, 3510, 3528, 3546, 3564, 3582, 3600, 3618, 3636, 3654, 3672, 3690, 3708, 3726, 3744, 3762, 3780, 3798, 3816, 3834, 3852, 3870, 3888, 3906, 3924, 3942, 3960, 3978, 3996, 4014, 4032, 4050, 4068, 4086, 4104, 4122, 4140, 4158, 4176, 4194, 4212, 4230, 4248, 4266, 4284, 4302, 4320, 4338, 4356, 4374, 4392, 4410, 4428, 4446, 4464, 4482, 4500, 4518, 4536, 4554, 4572, 4590, 4608, 4626, 4644, 4662, 4680, 4698, 4716, 4734, 4752, 4770, 4788, 4806, 4824, 4842, 4860, 4878, 4896, 4914, 4932, 4950, 4968, 4986, 5004, 5022, 5040, 5058, 5076, 5094, 5112, 5130, 5148, 5166, 5184, 5202, 5220, 5238, 5256, 5274, 5292, 5310, 5328, 5346, 5364, 5382, 5400, 5418, 5436, 5454, 5472, 5490, 5508, 5526, 5544, 5562, 5580, 5598, 5616, 5634, 5652, 5670, 5688, 5706, 5724, 5742, 5760, 5778, 5796, 5814, 5832, 5850, 5868, 5886, 5904, 5922, 5940, 5958, 5976, 5994, 6012, 6030, 6048, 6066, 6084, 6102, 6120, 6138, 6156, 6174, 6192, 6210, 6228, 6246, 6264, 6282, 6300, 6318, 6336, 6354, 6372, 6390, 6408, 6426, 6444, 6462, 6480, 6498, 6516, 6534, 6552, 6570, 6588, 6606, 6624, 6642, 6660, 6678, 6696, 6714, 6732, 6750, 6768, 6786, 6804, 6822, 6840, 6858, 6876, 6894, 6912, 6930, 6948, 6966, 6984, 7002, 7020, 7038, 7056, 7074, 7092, 7110, 7128, 7146, 7164, 7182, 7200, 7218, 7236, 7254, 7272, 7290, 7308, 7326, 7344, 7362, 7380, 7398, 7416, 7434, 7452, 7470, 7488, 7506, 7524, 7542, 7560, 7578, 7596, 7614, 7632, 7650, 7668, 7686, 7704, 7722, 7740, 7758, 7776, 7794, 7812, 7830, 7848, 7866, 7884, 7902, 7920, 7938, 7956, 7974, 7992, 8010, 8028, 8046, 8064, 8082, 8100, 8118, 8136, 8154, 8172, 8190, 8208, 8226, 8244, 8262, 8280, 8298, 8316, 8334, 8352, 8370, 8388, 8406, 8424, 8442, 8460, 8478, 8496, 8514, 8532, 8550, 8568, 8586, 8604, 8622, 8640, 8658, 8676, 8694, 8712, 8730, 8748, 8766, 8784, 8802, 8820, 8838, 8856, 8874, 8892, 8910, 8928, 8946, 8964, 8982, 9000, 9018, 9036, 9054, 9072, 9090, 9108, 9126, 9144, 9162, 9180, 9198, 9216, 9234, 9252, 9270, 9288, 9306, 9324, 9342, 9360, 9378, 9396, 9414, 9432, 9450, 9468, 9486, 9504, 9522, 9540, 9558, 9576, 9594, 9612, 9630, 9648, 9666, 9684, 9702, 9720, 9738, 9756, 9774, 9792, 9810, 9828, 9846, 9864, 9882, 9900, 9918, 9936, 9954, 9972, 9990, 10008, 10026, 10044, 10062, 10080, 10098, 10116, 10134, 10152, 10170, 10188, 10206, 10224, 10242, 10260, 10278, 10296, 10314, 10332, 10350, 10368, 10386, 10404, 10422, 10440, 10458, 10476, 10494, 10512, 10530, 10548, 10566, 10584, 10602, 10620, 10638, 10656, 10674, 10692, 10710, 10728, 10746, 10764, 10782, 10800, 10818, 10836, 10854, 10872, 10890, 10908, 10926, 10944, 10962, 10980, 10998, 11016, 11034, 11052, 11070, 11088, 11106, 11124, 11142, 11160, 11178, 11196, 11214, 11232, 11250, 11268, 11286, 11304, 11322, 11340, 11358, 11376, 11394, 11412, 11430, 11448, 11466, 11484, 11502, 11520, 11538, 11556, 11574, 11592, 11610, 11628, 11646, 11664, 11682, 11700, 11718, 11736, 11754, 11772, 11790, 11808, 11826, 11844, 11862, 11880, 11898, 11916, 11934, 11952, 11970, 11988, 12006, 12024, 12042, 12060, 12078, 12096, 12114, 12132, 12150, 12168, 12186, 12204, 12222, 12240, 12258, 12276, 12294, 12312, 12330, 12348, 12366, 12384, 12402, 12420, 12438, 12456, 12474, 12492, 12510, 12528, 12546, 12564, 12582, 12600, 12618, 12636, 12654, 12672, 12690, 12708, 12726, 12744, 12762, 12780, 12798, 12816, 12834, 12852, 12870, 12888, 12906, 12924, 12942, 12960, 12978, 12996, 13014, 13032, 13050, 13068, 13086, 13104, 13122, 13140, 13158, 13176, 13194, 13212, 13230, 13248, 13266, 13284, 13302, 13320, 13338, 13356, 13374, 13392, 13410, 13428, 13446, 13464, 13482, 13500, 13518, 13536, 13554, 13572, 13590, 13608, 13626, 13644, 13662, 13680, 13698, 13716, 13734, 13752, 13770, 13788, 13806, 13824, 13842, 13860, 13878, 13896, 13914, 13932, 13950, 13968, 13986, 14004, 14022, 14040, 14058, 14076, 14094, 14112, 14130, 14148, 14166, 14184, 14202, 14220, 14238, 14256, 14274, 14292, 14310, 14328, 14346, 14364, 14382, 14400, 14418, 14436, 14454, 14472, 14490, 14508, 14526, 14544, 14562, 14580, 14598, 14616, 14634, 14652, 14670, 14688, 14706, 14724, 14742, 14760, 14778, 14796, 14814, 14832, 14850, 14868, 14886, 14904, 14922, 14940, 14958, 14976, 14994, 15012, 15030, 15048, 15066, 15084, 15102, 15120, 15138, 15156, 15174, 15192, 15210, 15228, 15246, 15264, 15282, 15300, 15318, 15336, 15354, 15372, 15390, 15408, 15426, 15444, 15462, 15480, 15498, 15516, 15534, 15552, 15570, 15588, 15606, 15624, 15642, 15660, 15678, 15696, 15714, 15732, 15750, 15768, 15786, 15804, 15822, 15840, 15858, 15876, 15894, 15912, 15930, 15948, 15966, 15984, 16002, 16020, 16038, 16056, 16074, 16092, 16110, 16128, 16146, 16164, 16182, 16200, 16218, 16236, 16254, 16272, 16290, 16308, 16326, 16344, 16362, 16380, 16398, 16416, 16434, 16452, 16470, 16488, 16506, 16524, 16542, 16560, 16578, 16596, 16614, 16632, 16650, 16668, 16686, 16704, 16722, 16740, 16758, 16776, 16794, 16812, 16830, 16848, 16866, 16884, 16902, 16920, 16938, 16956, 16974, 16992, 17010, 17028, 17046, 17064, 17082, 17100, 17118, 17136, 17154, 17172, 17190, 17208, 17226, 17244, 17262, 17280, 17298, 17316, 17334, 17352, 17370, 17388, 17406, 17424, 17442, 17460, 17478, 17496, 17514, 17532, 17550, 17568, 17586, 17604, 17622, 17640, 17658, 17676, 17694, 17712, 17730, 17748, 17766, 17784, 17802, 17820, 17838, 17856, 17874, 17892, 17910, 17928, 17946, 17964, 17982, 18000, [...], 18

So the LCM for 9 and 18 is 18

Another method to find LCM for numbers 9 and 18 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors: