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Large numbers to 2 significant figures
By Anonymous on Friday, December 3, 1999 - 11:49 pm:

My 10 year old is not sure, nor am I. I can handle significant numbers after a decimal point, but what is something like 1996 to two significant numbers?

By Alastair Fletcher (Anf23) on Monday, December 6, 1999 - 04:09 pm:

Hi,

If you have an unfamiliar problem, then sometimes the best thing to do is turn it into a more familiar one. So, if, for example, you want to know 1234 to 2 significant figures, can we turn this into something more familiar?

How about 0.1234? What is that to 2 significant figures? Once we know this, we can go back to the original problem. So, in my example, 0.1234 is 0.12 to 2 significant figures, and so 1234 is 1200 to 2 signicant figures.

See if you can now do your problem.

Hope this helps,
Alastair

By Dan Goodman (Dfmg2) on Wednesday, December 8, 1999 - 03:09 am:

Another angle on this problem. To write any number with 2 significant figures, you look for the first digit (reading from the left) which isn't 0, then you count along another digit and round up the digits after that.

Some examples:

1234 goes to 1200 (rounding 234 to the nearest hundred gives you 200)
01234 goes to 1200 (as the 0s at the beginning aren't significant)
4567 goes to 4600 (rounding 567 to the nearest hundred gives you 600)
4002 goes to 4000 (not 4002)

Dan Goodman.