Ans. To differentiate between odd and even numbers, we need to check the units digit. If the units digit is 0, 2, 4, 6, or 8, then the number is even. If the units digit is 1, 3, 5, 7, or 9, then the number is odd. For example, 24 is even because the units digit is 4, while 37 is odd because the units digit is 7.