Video Transcript
How many nines are there in 45036?
To find the answer to this question, we need to divide 45036 by nine. Now, 45036 seems like quite a large number, five-digit number. So we might think straight away, we need to use short division to find the answer. But not every calculation that involves a large number is tricky. In this case, we can find the answer very quickly by using partitioning to help. And the reason why we’d look to partition this number is that we can see numbers that are related to the nine times table in it. 45000 in 45 is in the nine times table. And then on the end, we have 36 and 36 is a multiple of nine too. And so, we can partition the number into 45000 and 36.
First of all, let’s divide 45000 by nine. What fact can we use to help us? We know that 45 is a multiple of nine. Nine, 18, 27, 36, 45. There are five nines in 45. So 45 divided by nine equals five. So 45000 divided by nine must be 5000. Next, we need to ask ourselves how many nines are in 36. Nine, 18, 27, 36. The answer is four. Four times nine equals 36. And so, 36 divided by nine equals four.
So to find the number of nines in 45036, we don’t need to use short division. We just need to divide 45000 by nine, 36 by nine and finally add the two together. 5000 plus four equals 5004. And there’s our answer. Let’s use short division just to check that our answer is correct.
There are no nines in four. So we can cross through the four digit and write it next to the five. How many nines in 45? We’ve already worked that out. There are five nines in 45 and there’s no reminder. There are zero nines in zero. And there are also zero nines in three. Three is too small. So we can cross through the three and write it next to the six. Finally, how many nines are there in 36? Again, we’ve already work this out. The answer is four.
And so, the number of nines in 45036 using two different methods we found that the answer is 5004.
