Find the missing number.
The diagram that we’re given in this question is a part-whole diagram. The whole amount is 594. And we can see this in the circle at the top. And then, this whole amount is split, or partitioned, into two parts. There’s the number five in the left-hand circle. And there isn’t a number in the right-hand circle. So, this must be where we need to write our missing number.
So, we could think to ourselves, what do we partition 594 into? Five and what? But if we look more closely at the diagram, we can see that this isn’t what’s happened. The number five has a label by it. And the label tells us that this circle represents the number of hundreds. And of course, we know this is true. If we write out the number 594, we know that the digit five is in the hundreds place. It shows us that there are five hundreds.
Now, the circle with our missing number in is interesting. It’s labeled number of ones. So, we need to partition 594 into a number of hundreds and a number of ones. We’ve already said that the number of hundreds is five; this is equal to 500. But 594 also contains nine tens, which is the same as 90, and four ones. How many ones are there in 94?
Well, the first thing we can say is that each 10 is worth 10 ones. So, let’s count in 10s for each 10 that we’ve got, 10, 20, 30, 40, 50, 60, 70, 80, 90. This is no surprise; nine tens are worth 90. And we’ve got four more ones in the ones column. So, the number of ones we have in 94 is 94. Our missing number to complete our part-whole diagram is 94. 594 can be split into five hundreds and 94 ones. Our missing number is 94.