# Video: Identifying an Odd Number Using Its Properties

Which is the odd number, 7134, 80188, 27, or 4622?

02:08

### Video Transcript

Which is the odd number, 7134, 80188, 27, or 4622.

This question asks us to identify the odd number. And we’ve got four possible answers. 7134, 80188, 27, and also 4622. We know that the odd digits are one, three, five, seven, and also nine. And if we look at our four possible answers, we can see some examples of these odd digits. There are some ones. There’s a three. We don’t have a five or a nine. But there are a couple of sevens too. So there are digits within our four possible answers. But only one of our answers is an odd number.

An odd number is a number that ends with an odd digit. It doesn’t matter what the other digits in the number are. But if it has an odd number of ones, it’s an odd number. So really, we could forget about all the other digits in the question. We just need to concentrate on the number of ones. Our numbers contain four ones, eight ones, seven ones, and two ones. Can you spot the odd number? Well, two, four, and eight are all even digits. The only odd digit is seven. And so we know the odd number is the number that has seven ones. And if we put our missing digits back in, we can remind ourselves that that number is 27.

Only one of our four possible answers has an odd digit in the ones place. We know seven is an odd digit. And so the only odd number out of our possible four answers is 27.