The LCM of 7 and 10 is 70. Multiples of 7 are 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, and so on. Multiples of 10 are 10, 20, 30, 40, 50, 60, 70, 80, an so on. So the least common multiple of 7 and 10 is 70. 70.