Write 286 correct to the nearest 10.
So first of all, let’s think about 286. Well, 286 written here in place values is we’ve got two hundreds, eight tens, and six units. Okay, so we want to write this correct to the nearest 10. So therefore, it’s actually gonna be the eight that we’re gonna be looking at, because actually, as we said, this is in the tens column.
So whenever I’m looking to actually round a number, what I’m gonna do is draw a line after the number that we’re actually looking at. So we’ve already established that it’s the eight that we’re looking at, because we want it to the nearest 10. So then what we’re gonna do is look to the right of this line and look at the digit there.
Now this digit will actually determine what will happen to our eight, because if we take a look at this six, so like we said the digit after the one that we’re actually looking at, then we can actually see that if it’s greater than or equal to five, then the eight will round up to nine. However, if it’s less than five, then the eight will remain unchanged.
Well, as we’ve already stated, it is a six. So therefore, it’s going to be greater than or equal to five. So therefore, what we’re gonna have to do is actually round the eight up to a nine, which is therefore gonna give us 290. And that’s because we’ve rounded up our eight to a nine.
Worth pointing out at this point, don’t fall into the mistake that some students make. It’s a common mistake is they write 29 because they think, “Okay, great! I’ve rounded my eight to a nine, so I can just get rid of the number that was after the eight.” But we can’t do that because actually then that would give us an answer of 29, which is nothing near the 286 that we started with. So therefore, what we can say is that 286 is equal to 290 if it’s rounded to the nearest 10.