Video Transcript
Which number is a factor of 14? Three, four, six, seven, or 28?
Remember that factors are numbers which when we multiply them together, they make another number. Our question gives us five numbers and asks us to identify which one of them is a factor of 14. There are two ways we could find the answer to this question.
The first method we could use is to look at each of the five numbers in turn. We could try to see which one do we multiply by another number to give us 14. Our second method could be to start with the number 14 and ask ourselves, what are all the factors of 14? We’ll then decide which of the five numbers appears in our list.
Let’s begin by using the first method. And we’ll look at each of the five numbers in turn. Is three a factor of 14? Let’s remind ourselves of the multiples of three. Three, six, nine, 12, 15. Three is a factor of 15, but it’s not a factor of 14.
Which numbers could four be a factor of? Four, eight, 12, 16. We’ve now gone past 14 again. Four is a factor of 16, not 14. Is six a factor of 14? Well, we know it’s a factor of six, of 12, and 18. We’ve already gone past 14 now. Six is not a factor of 14. Is seven a factor of 14? Seven is a factor of seven, and also, it’s a factor of 14.
Be careful with the last number. 28 is larger than 14, so it can’t be a factor of 14. But it might be easy to get confused here, because 14 is actually a factor of 28. Two 14s make 28. So be very careful with this one.
The number that is a factor of 14 is seven. Let’s use our second strategy, just as a way to check that we’ve got the correct answer. Remember, our second strategy was to list all the factors of 14, and then we’ll see whether seven is one of them.
Which numbers can we multiply together to give 14? Or in other words, if we had 14 counters, what different arrays could we make? We could make one row of 14 counters. So, a factor pair that makes 14 is one times 14. And the only other way to arrange the counters is as two rows of seven, or seven rows of two. So, 14 has four factors, one, two, seven, and, of course, 14. And as we’ve seen already, only one of these four factors is in the orange box. The number that is a factor of 14 is seven.
