I am doing a paper on children in the inner-city.  I was trying to
find a number or an estimate of the number of children who live in
metropolitan areas.  Can you help?

Hello.

I'll assume that you want statistics for the United States.

"More than 21 million children live in urban settings."
Christian Science Monitor
http://search.csmonitor.com/durable/2000/08/24/p17s1.htm

I checked data at the Census Bureau. And the CS Monitor is just about
right.

As of March 2002, there were an estimated 20,971,000 children living
in what the Census Bureau calls "Central City/Metropolitan Statistical
Area."

From the "Children's Living Arrangements and Characteristics March
2002" :

Type of residence:     (number of people under 18 in thousands)
Central city/Metropolitan Statistical Area: 20,971
Outside central city/MSA (i.e., suburban): 38,194
Outside MSA (i.e., rural): 13,155

Source: Table 8, page 16, "Children's Living Arrangements and
Characteristics March 2002," published June 2003 by US CENSUS BUREAU:
http://www.census.gov/prod/2003pubs/p20-547.pdf

[ Note that this document is in PDF format, so the Adobe Acrobat     
Reader is required. If you don't have that, please visit Adobe's web
site:
http://www.adobe.com/products/acrobat/readstep2.html  ]  


search strategy:
"million children live", urban
census.gov, "current population survey", children

I hope this helps.

Thanks I checked the census and failed to see it.

Thank you for the tip.
-juggler