In mathematics, "less than" is a comparison between two numbers. It is represented by the symbol < (less than sign).
When comparing two numbers, if the number on the left is smaller than the number on the right, then we say that the left number is "less than" the right number.
3 < 5
In this example, 3 is less than 5 because 3 is smaller than 5.
It's important to note that the "less than" comparison is directional. In the example above, if we reverse the numbers and compare 5 with 3, then 5 is not less than 3, and we would write it as: 5 > 3 (5 is greater than 3).