Don't use calculator

[jamesravid]

Find the value of 2006^2 - 2007 * 2005 + 2008 * 2004 - 2009 * 2003

-- James.

[SachinDeo]

Without using calculator I got the result as 6. Kindly update whether my finding is right

[jamesravid]

Sachin,
Actually solution is more important for this question. So provide us your solution.

-- James

[anushya]

Accept Sachin's result.

[hsundar]

a = 2006
Expression = a^2 -(a+1)(a-1)+(a+2)(a-2)-(a+3)(a-3)
Upon simplification you get 6

[TigerElango]

I got 5.i may be correct.but tell the actual way of doing it.