The product of two numbers is 15. One of the numbers is five. What is the other number?
Product is a keyword here. So let’s remind ourselves of what that means. For example, two times five is 10. And we can say 10 is the product of two and five.
In our question, we can see that the product of two numbers is 15. So let’s write that down. So we have our two numbers and the product 15.
We know that one of the numbers is five. And we have to find the missing number. In other words, what number times five is 15? We’re going to use related division facts to help us find the other number.
And we use the numbers that we already have, 15 divided by five. We know if we’re dividing by five, that means there will be five groups. So let’s draw those groups. There we have our five groups.
Now we need to divide 15 into those five groups. One, two, three, four, five, six, seven, eight, nine, 10, 11, 12, 13, 14, and 15. Each group has three. So we have five groups of three.
15 divided by five is three. So 15 is the product of three and five. The missing number is three.