### Video Transcript

Three numbers add up to 57. The first number is 40. The second number is seven. What is the third number?

Let’s listen to the question again. Three numbers add up to 57. The first number is 40. The second number is seven. What is the third number? So we’re told that the total of three numbers is 57. We need to remember this because this is the total that we need to make. We’re told what two of the numbers are. We don’t need to remember these because we have these written down already. The question told us that the first number was 40. The second number was seven. And we need to find the third number.

To help us find the third number, let’s think about how much we have already. 40 plus seven equals 47. We already have 47. So what do we add to 47 to make 57? 47 has four tens and seven ones. 57 has five tens but still the same number of ones, seven ones as well. So we can see that the only difference between these numbers is that 57 has got one more ten. We’ve added 10. 47 add 10 makes 57.

Our first two numbers made a total of 47. And so to make 57, we needed to add another 10. Three numbers add up to 57. The first number is 40. The second number is seven. And we found that the third number is 10.