Decimals Question

[Gee]

Which one is bigger?

4.7 or 4.70?

5.4 or 5 40/100 (it is a fraction)

Any comments?

[Guest55]

Which one is bigger?

4.7 or 4.70?

5.4 or 5 40/100 (it is a fraction)

Any comments?

I'm guessing that what they might be getting at here is that 4.7 is correct to one dp whereas 4.70 is more accurate.

4.7 could be bigger but could also be smaller ... is there an answer?

[Gee]

Sorry, I thought nobody has responded as I didn't receive email.

Unfortunately, I don't have answer for the questions. Anyway, I agree with you too Guest55.

[Guest55]

You don't get an e-mail when someone answers, you need to keep an eye on the thread or use 'view new posts'.

[Tinkers]

If you tick the 'Notify me when a purely is posted' box when you post (it's under the box you type in), you should, in theory, get an email when someone else posts on the thread. If you haven't ticked that, then you won't get an email notification.

[Goodheart]

Which one is bigger?

4.7 or 4.70?

It could also be that they're trying to ascertain whether or not the child understands that:

• although 470 is clearly larger than 47, the introduction of the decimal point changes the "meaning" of those digits entirely, and
• 4.7 and 4.70 actually represent the same number.

[Guest55]

Technically, 4.7 is not the same as 4.70 - the additional zero shows the value is correct to two dp.

It is aa poor question imho.

[wangxiaosara]

Is this type question really in the 11 plus? I very much doubt!

In theory, 4.7 may possibly larger than 4.70 ( can't believe I am saying this) if 4.7 was a rounded up number, i.e. Number 4.71 - 4.74 rounded to 1 dec place. If just consider the figure value, then 4.7 equals to 4.70.

[Aethel]

I agree. 4.7 is the same as 4.70 UNLESS rounding/estimation has been mentioned.

The reason for this (rusty double A level maths!) is simply one of convention:
Whenever a digit is not specified it is assumed to be zero.
This is to save you writing out a near-infinite number of un-necessary zeroes in any decimal number. Where the number in each place point is not zero it should be specified, or rounding to the nth decimal place actively mentioned (in which case .

So writing 2 is the same as writing 00000002.00000000, but much clearer.

2.00 to two DP, however, may actually be 2.001

The original question is not well worded!

[Surferfish]

I'd have thought the simple answer is just that they're equal. I think the rounding debate might be over-complicating what they're looking for.

Here's a similar one (more fun/interesting IMO), to think about.

Which is bigger?
0.999...(recurring) or 1?