How can you determine if a number is odd?

To determine if a number is odd, the critical characteristic is its final digit. A number is classified as odd if it ends in 1, 3, 5, 7, or 9. This is based on the properties of the place value system in base-10, where the last digit reveals whether a number is odd or even.

Numbers that end with 0, 2, 4, 6, or 8 are classified as even, as they can be precisely divided by 2. In contrast, the defining factor of odd numbers is that when divided by 2, they yield a remainder of 1, aligning with the digits that signify oddness.

Moreover, stating that a number has no factors would not directly assess its oddness or evenness, as all natural numbers have at least a factor of 1 and themselves. Thus, identifying these distinctive ending digits is the clearest and most straightforward method of determining if a number is odd.