Sum last N rows in column

[jfrechette]

My book is made up of three columns.
A= dates
B= score
C= sum of last 5 scores

Beginning on March 3, I sum the scores for the last 5 days (B1:B5) and report that in C5.
For March 4, I sum the scores for the last 5 days (B2:B6) and report in C6.

Is there a formula that I can use to count the last N rows (in this case, 5) on a daily basis?


2/27/2013 2044
2/28/2013 2802
3/1/2013 1986
3/2/2013 1487
3/3/2013 1172 9491
3/4/2013 1953 9400
3/5/2013 2645 9243
3/6/2013 4090
3/7/2013 2234
3/8/2013 2005
3/9/2013 1118
3/10/2013 1178
3/11/2013 1796
3/12/2013 2827
3/13/2013 5332
3/15/2013 2042
3/16/2013 1267
3/17/2013 1149
3/18/2013 1925
3/19/2013 2395
3/20/2013 2530
3/21/2013 2655
3/22/2013 2125
3/23/2013 1882
3/24/2013 2449
3/25/2013 2750

[Pauleyb]

=sum(offset($b$1,count(b:b)-5,0,5))

[etaf]

if you put
=sum(b1:b5) in c5 and then copy down
doesnt c6 become
=sum(b2:b6)
anyway

[jfrechette]

Thank you! I think I try to over complicate most things!