Question Video: Finding the Greatest Whole Number That When Rounded to the Nearest Ten Gives a Certain Result Mathematics

Video Transcript

What is the greatest whole number that when rounded to the nearest ten gives a result of 1190?

The number mentioned in our question is a multiple of 10. We know this because it ends in a zero. Now, often we’ll want to round the number to the nearest ten to make our calculation easier. Some numbers will be less than the multiple of 10 and we’ll round them up to the nearest ten. And, some numbers will be greater than the multiple of 10 and we’ll have to round them down to the nearest ten. Our question asks us to find a whole number that when we round it to the nearest ten gives a result of 1190. But, it doesn’t ask for any whole number. It asks for the greatest whole number.

Now, the greatest whole number is going to be larger than 1190, not less than it. It’s going to be one of the whole numbers that we round down to 1190. So, let’s think about all the numbers that are larger than 1190 and that we can round down. Firstly, 1191 rounds to 1190, as does 1192, 1193, 1194. But, when we get to 1195, we reach a number that ends in a five. This is actually the midway point between 1190 and the next multiple of 10 which is 1200.

And, when we’re thinking about the digit five, we always round upwards. So, actually we’d round 1195 upwards to 1200. This is not a number that rounds to 1190. And so, the greatest whole number that rounds to 1190 must be one less than 1195. The greatest whole number that when we round it to the nearest ten gives a result of 1190 is 1194.