The grid shows a list of numbers: one, four, seven, nine, and 10. From the list, write down a multiple of four and a prime number.
So in order to do this, we must understand the word “multiple” and “prime.” A multiple of four is any number in the four times table. Four times one is four, which shows up in our list here. Four times two is eight. Four times three is 12. But notice, our list of numbers has the largest number as 10. So now that we’re at four times three equaling 12, that number is already too large for this list. So the only multiple of four shown in our list would be four.
Next, we need to find a prime number. A prime number is a number only divisible by itself and one and is larger than one. So right away, we know that we can exclude one because our number that’s prime has to be larger than one.
So is four only divisible by itself and one? Yes, it is divisible by itself. Four divided by four is one. And yes, it’s divisible by one. Four divided by one is four. However, those aren’t the only numbers that it’s divisible by. Four is also divisible by two, so four is not a prime number.
Next we have seven. It’s divisible by itself and one. However, it’s not divisible by any other number. There isn’t any other number that goes evenly into seven. So seven must be a prime number. Nine will not be a prime number because nine is also divisible by three. 10 will not be a prime number because it’s also divisible by five and two. Therefore, from our list of numbers, four is the multiple of four and seven is the prime number.