1. The problem is to find all multiples of 5 that are less than 51. 2. Multiples of 5 are numbers that can be written as $5n$, where $n$ is a positive integer. 3. We need to find all integers $n$ such that $5n < 51$. 4. Dividing both sides of the inequality by 5, we get $n < \frac{51}{5} = 10.2$. 5. Since $n$ must be a positive integer, $n$ can be 1, 2, 3, ..., 10. 6. The multiples of 5 less than 51 are $5 \times 1 = 5$, $5 \times 2 = 10$, $5 \times 3 = 15$, $5 \times 4 = 20$, $5 \times 5 = 25$, $5 \times 6 = 30$, $5 \times 7 = 35$, $5 \times 8 = 40$, $5 \times 9 = 45$, and $5 \times 10 = 50$. 7. Therefore, the multiples of 5 less than 51 are: $5, 10, 15, 20, 25, 30, 35, 40, 45, 50$.